Title: Enigmas and Riddles in Literature, Author: Eleanor Cook
Title: Old English Enigmatic Poems and the Play of the Texts, Author: John D Niles
Title: Untying the Knot: On Riddles and Other Enigmatic Modes, Author: Galit Hasan-Rokem
Title: Infidel Poetics: Riddles, Nightlife, Substance, Author: Daniel Tiffany
Title: Spanish Riddles & Colcha Designs / Edition 1, Author: Reynalda Ortiz y Pino Dinkel
Title: Jokes: Philosophical Thoughts on Joking Matters / Edition 2, Author: Ted Cohen