The Dictionary of the Khazars: A Lexicon Novel was written by the Serbian novelist Milorad Pavic (1984). As the subtitle impies, the novel takes the form of a lexicon or encyclopedia; indeed, it comprises three parallel, cross-referenced lexicons, in each of which the entries are constructed from the point of view of one of the three religions Judaism, Christianity, and Islam.
"Tlön Uqbar Orbis Tertius" is the title of a short story by the Argentine writer Jorge Luis Borges that revolves around a rare (possibly unique) edition of the Encyclopedia Britannica containing an entry on an otherwise unknown country called Uqbar. As the story unfolds, it appears that Uqbar is part of a conspiracy of thinkers to create an entire new world, Tlön, by imagining it in all its details.
Originally published in Italy in 1981, the Codex Seraphinianus appears to be an encyclopedia for a world very different from Earth. It is profusely illustrated with colored-pencil drawings of fantastic beings, many of which are hybrids between categories that we generally consider wholly separate: animal-machine, vegetable-mineral.