There are at present fairly good reasons for the fact that, in the study of Buddhist thought in Tibet, attempts to answer such questions as the specific texts and interpretations that had impacted their authors, the individuals with whom they had studied, whom they in turn influenced, as well as their relative importance for the tradition as a whole are by and large outstanding.
L. W. J. Van Der Kujip (2003), p. 388.
Klong chen rab 'byams (1308-1364), a great lover of pseudonyms, is also known by the names “Klong gsal dri med, rDo rje gzi brjid, rDo rje sems dpa', Dri med 'od zer, Blo gros mchog ldan, Tshul khrims blo gros, Ngag gi dbang po, Padma las grol, sNa tshogs rang grol, bSam yas pa”, but also Padma las ’brel rtsal and Byar med klong yangs,  sometimes embellished with epithets such as “the follower of the Supreme Vehicle” (theg pa mchog gi rnal 'byor pa), " the omniscient " (kun mkhyen), etc. To this list we must add: Kun mkhyen chos rje (more of a title than a name, but the line is fine), Phan pa bzang po, Nam mkha'i rnal ’byor and Gu yang blo bde .
The most frequent of these pen names are, without question: Dri med ’od zer, Klong chen rab 'byams, Kun mkhyen Ngag gi dbang po and Tshul khrims blo gros. rDo rje gzi brjid is found only in the Trilogy that dispels darkness (Mun sel skor gsum), relating to the Guhyagarbhatantra, and Padma las ’brel rtsal, in some texts of mKha’ ’gro yang tig. It is only under the name of Klong chen rab ’byams that he is generally mentioned, or in its abbreviated form, Klong chen pa (formed by posterity, certainly in imitation of the names under which the major authors of Tibetan philosophy are known, for example, sGam po pa, Dol po pa, Red mda’ ba, Tsong kha pa, Go rams pa, etc.).
As has been said, he is undeniably the author whose work is held in the highest regard in the ancient tradition (rNying ma) of Tibetan Buddhism, and he is even the object of a personal cult which, although not excessively widespread, is nonetheless proven. A number of later masters of the rNying ma school are said to have written all or part of their works under his visionary inspiration, notably gTer bdag gling pa (1646-1714) and especially ’Jigs med gling pa (1729-1798). As for the latter, for example, his famous Chariot of the Two Realities (bDen gnyis shing rta), a self-commentary on his Treasure of Qualities (Yon tan mdzod), is practically a patchwork of innumerable passages taken from the works of Klong chen rab ’byams. Moreover, in ’Jigs med gling pa’s “treasure” (gter chos, cycle of revealed teachings), the “arch-secret” guru-yoga practice, called Sealed by a biṇḍu (Thig le’i rgya can), is centered on Klong chen rab ’byams and not on Padmasambhava or any other idealized figure of the master.
The bulk of his writings are collected in the following collections: the Seven Treasures of the Supreme Vehicle (Theg mchog mdzod bdun), the Three Quintessences (Yang tig gsum), the Remission Trilogy (Ngal gso skor gsum), the Trilogy Dispelling Darkness (Mun sel skor gsum), and the Small Trilogy of Self-Reliberation (Rang grol skor gsum). To this must be added a large number of works that are smaller in scope and less well known, but often very interesting (notably the other texts contained in the two volumes of Miscellaneous Works (gSung thor bu), to which must perhaps still be added The Triumph over Error (’Khrul pa rab 'joms, no. 31), a polemical treatise (of dubious attribution, however), and (more certainly) the general presentation of the tantras, entitled The Melodious Thunderclap [like the voice of] Brahmā (sNgags kyi spyi don tshangs dbyangs ’brug sgra), no. 55).
In spite of this considerable prestige and the veneration with which his work and his person are surrounded, it is disconcerting that, in his posterity, little attention has been paid to clarifying the difficult points, or even to proposing a truly satisfactory compilation of complete works.
As for the first aspect, although the works of the later rnying ma pa masters are full of borrowings from the Seven Treasures and the Three Quintessences, many points of his work are nevertheless generally ignored - proof that it is not read with the full attention it requires.
As far as we know, only ’Ju Mi pham (1846-1912) attempted to clarify Klong chen rab ’byams’ own positions in his Abstract of the exposition of the philosophical systems of the Treasury of Wish-fulfilling Jewels and in his treatise on the difficult points of the same Treasury of Wish-fulfilling Jewels. But, on the one hand, these two writings present a certain character of superficiality - they are rather, in spite of the generally excellent level of Mi pham’s production, tools for a first approach of our author’s texts than in-depth, problematized works of sufficient radicality. On the other hand, they focus on a single work, which is certainly of great importance because of its late and synthetic position, but which does not cover the whole field of the master’s thought, far from it.
As for the second aspect, it is significant enough that there is no edition today that includes all the preserved works (a gsungs 'bum) of this author.
In short, it could be said that Klong chen rab ’byams is in a way fetishized, more idolized than really studied. It is true that this cannot surprise anyone who has been close to the rNying ma school, since the current state of mind of its followers is indicative, to a certain extent, of that which may have prevailed in earlier centuries. If, on the other hand, some dge lugs pa monks often seem full of naive confidence (because they are based on a too limited knowledge of the canonical texts) as to the possibility of reducing the whole of Buddhism to a rather small number of clear and univocal formulas, the rNying ma pa, for their part, are sometimes upset by the slightest question highlighting a doctrinal difficulty.
Very often, it seems to them that faith is the prerequisite for study, so that one must somehow believe what one does not yet understand, “faith in search of intelligence,” according to the Augustinian formula; and, moreover, insofar as traditional formulations seem to them to be unsurpassable, simple repetition often takes the place of understanding. The adept is supposed to have validated by direct perception, in his meditation, the truth of what the masters of the past have said; and it is with compunction, with an air of understanding, that he will repeat obscure speculative and mystical statements learned by heart.
We certainly do not have to pronounce on the reality of this intuitive understanding of traditional doctrines; it is outside the scope of the present study. But the fact is that the immense corpus of the literature of the Ancient School, even more than the canon of the other schools, contains very disparate material, excessively interesting, but which, more often than not, shatters the overly narrow frameworks in which the masters, for the sake of pedagogical simplification, have tried to arrange them (see Achard’s (1999) remarks on “aberrant doxographies,” or the fruits of Philippe Cornu’s ongoing research on the wavering of the doctrine of the bar dos or post-mortem intermediary states, etc.). This is why it is not difficult to point out contradictions, or at least paradoxes, within this tradition, which is reputed to be indisputable - which, as our repeated experience attests, often provokes upset reactions. Thus one is confronted with a tradition which seems to be anxious to give itself a clear and smooth appearance by denying part of its own richness, or by fear that free personal examination will lead to ruinous conclusions.
 This is the list he himself gives in the Grub mtha' mdzod (no. 33, p. 403-404). We shall return later to these pseudonyms, insofar as it has been believed - wrongly - that they play an important role in establishing the chronology of the works.
 Name of the "discoverer" (gter ston) of the mKha' 'gro snying thig (difficult to date; it will be mentioned in the paragraph devoted to rGyal sras Legs pa), which Klong chen rab ’byams sometimes uses in the colophons of the mKha’ ’gro yang tig, the corpus devoted to the exegesis of the mKha’ ’gro snying thig.
 Here is why these two pseudonyms are not listed in the Treasury of Philosophical Systems (Grub mtha' mdzod, no. 33): (1) when he signs with the name Padma las ’brel rtsal (especially in the Quintessential Drop of the ḍākiṇī (mKha 'gro yang tig), Klong chen rab ’byams certainly wants to fade behind the character he embodies (the discoverer of the Essential Drop of the ḍākiṇī (mKha' 'gro snying thig) - who, incidentally, was not himself supposed to be an author, but only the bearer of a revelation. (2) The pseudonym Byar med klong yangs appears only in the Deep Quintessence (Zab mo yang tig). However, as we shall see, the composition of this cycle had not been completed when the Treasury of Philosophical Systems was written. Moreover, in the present state of research, especially for the texts of the three Yang tig, it is difficult to determine to what extent Klong chen rab ’byams was an author and to what extent he was an editor, or even, in the middle position, an editor of earlier materials that he had compiled and classified.
 sMyo shul chos ’byung, p. 327 (see bibliography in the author’s name, sMyo shul mkhan po).
 Better known as Shing rta chen po (no. 217). It occupies the greater part of vols. I to IV of the mKhyen brtse edition of the Complete Works. This text is quite studied in the present rnying ma pa monasteries.
 To establish this in detail would not be very difficult, apart from the length of the task and its very meticulous nature. We give an example at one point in this work, where we compare some passages from the Treasure of the Supreme Vehicle (Theg mchog rin po che’i mdzod, no. 96) and the Treasure of the Meaning of Words (Tshig don rin po che’i mdzod, no. 199) with the parallels in ’Jigs med gling pa. The underlined numbers refer to the general table of Klong chen rab 'byams’ works that closes this section.
 Klong chen snying gi thig le las | yang gsang bla ma’i sgrub pa Thig le'i rgya can, quoted edition, vol. Da (XI), pp. 329-335. In the context of rDzogs chen, and more specifically of sNying thig, the term biṇḍu / thig le, here still translated as “drop,” connotes particularly iridescent apparitions, mainly in the form of discs, but possibly in other geometrical forms, which manifest in the meditations of the Thod rgal (much will be said about them later).
 Yid bzhin mdzod kyi Grub mtha’ bsdus pa and Yid bzhin mdzod kyi dka’ ’grel. We return to these texts later. They can be found in vol. XXI of the mKhyen brtse edition of the Complete Works of Mi pham and in the appendix to the volumes devoted to the Yid bzhin rin po che’i mdzod in the Dodrupchen and Tarthang Tülku editions, along with two other texts devoted to the Yid bzhin rin po che’i mdzod - a commentary on chapter XVIII of this treatise, on the one hand, and a table of contents (sa bcad).
The continuation is here.