i think search starts out identifying all the 30040s and searchable through their titles/authors. A high level contextual view, or how we generally look through books.
The interesting concept comes at the analysis/search level between individual zettles. Been thinking about a word embedding kind. Tags could "model" and the id of the referenced event with the coordinates in the note.
General dvms would have a field day with existing embeddings AND you can plot/organize through their embeddings forbthe users to find connections. Select individual zettles that are exactly what you are interested in.
We're given books and papers with an implicit task of finding the gold in the text. Here we have the coordinates of all raw materials. You find the zettle that you care about and read the surrounding context or insert it into the context of your ideas.