In 1993 I participated a contest with my girlfriend. We needed to find lots of factoids in literature, for instance we had a phrase from some obscure book and

In 1993 I participated a contest with my girlfriend. We needed to find lots of factoids in literature, for instance we had a phrase from some obscure book and needed to find what book it belonged too; then a longer block of text from Proust, but which book? In fact the passage (about Venice, its tiled roofs) is present at two places in "la Recherche", but with a couple of words changed. Another thing to find was the mystery component of a mint julep as per Mark Twain. We spent something like two weeks at the library, thumbing through hundreds of books (all of Mark Twain, all of Borges, all of Proust, and some others). All of this would be a 20 minutes search nowadays.