 Even when translated into English from his native Spanish, the work of Jorge Luis Borges is some of the most professional and impressive use of language you will ever encounter. His tiny short stories are some of my favorites. The real gem here is the library of Babel, an infinite library that fills an entire universe. The books that fill the shelves contain every possible combination of letters imaginable. The librarians who populate this universe are looking for a mythical index which will list all possible books. Someone once described this story as a written version of an MC Escher drawing and it's a good analogy. This pocket penguin series is an impressive collection of 70 tiny books that were released a few years ago in celebration of penguins 70th anniversary. I'll let you take a look at the list of titles and authors here. You won't find a wider variety, so look up the series they are not expensive.