In response to John Bird's comments, here is a list of Twain references from a Jeopardy database. It may take 20-30 seconds to gather the results:
Hint: Also search for "Kent Rasmussen" as well. He appeared both as a contestant and in a "question to this answer"--
"Calaveras County" & "Hannibal" are entries in R. Kent Rasmussen's book this man "A to Z."