R. Kent Rasmussen is the holder of a UCLA doctorate in history and a retired reference-book editor. He has long been recognized as a leading world authority on Mark Twain, about whom he has published thirteen books. Those volumes include such now-standard reference works as Mark Twain A to Z; its expanded revision, Critical Companion to Mark Twain; and The Quotable Mark Twain. Mark Twain books that he has edited include four volumes of critical essays; several collections of Mark Twain's own writings, including the Penguin Classics edition of Autobiographical Writings; and Mark Twain for Dog Lovers, a Lyons Press publication. He lives in Thousand Oaks, CA.