The stemma of the Kangyur have been well researched in particular by Helmut Eimer.
From the en.wikipedia.org
The process of constructing the stemma is called recension, or the Latin recensio.
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Relations between the lost intermediates are determined by the same process, placing all extant manuscripts in a family tree or stemma codicum descended from a single archetype.
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He also noted that, for many works, more than one reasonable stemma could be postulated, suggesting that the method was not as rigorous or as scientific as its proponents had claimed.
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More examples
A tree diagram showing a reconstruction of the transmission of manuscripts of a literary work
Lineage: the descendants of one individual; "his entire lineage has been warriors"
Simple eye: an eye having a single lens
(Stemmas) A simple eye refers to a type of eye design or optical arrangement that contains a single lens. "Simple" in this case does not refer to the number of cells present in the eye or the visual acuity of the eye. ...
A family tree or recorded genealogy; In the study of stemmatics, a diagram showing the relationship of a text to its manuscripts; One of the types of simple eyes in arthropods
(plural: stemmata): Simple eye of a caterpillar, usually arranged in a group of six on each side of the head (see Figure 3).
Stem. A diagram presenting the phylogeny of a manuscript tradition in visual form. Unlike a strict cladogram, a stemma may exhibit ancestors and reticulation (mixture between lineages).
1) in Latin, a pedigree. 2) in Italian, a coat of arms.