Berrington, Benj. S., and John S. Berrington. 1905. English Riddles: With Explanations and Notes in Dutch. Purmerendm NL: J. Muusses. ⍽▢⍽ Many of the "riddles" in this Dutch book are pun - playing with "look-alike" sounds on words.

Brown, Thomas A., and T. J. Carey. 1906. The New Pun Book. New York: Carey-Stafford. ⍽▢⍽ The source of most of the pun above.

Culler, Jonathan, ed. 1988. On Puns: The Foundation of Letters. Oxford, UK: Basil Blackwell. ⍽▢⍽ This is a collection of essays by different writers, some of them witty and graceful, others less so - about puns and punning, its history and criticism. The language of some of the writers may not be according to the guidelines of Plain English. You'll have to take that in stride.
    Pun is an ancient form of wit, and well suited to children and upwards. Pun can be amusing and revealing, quite clever, or really witty. Witty pun is also part of the cultural heritage from antiquity, expressed in Latin and other, developing languages. There is a wide range to explore along with considering different views and ways of word play both in classical literature and in late medieval poetry and to puns interpreted in psychoanalysis, as well as the role of puns in concept formation. Jonathan Culler's work suggests that taking puns seriously might in time improve one's thinking, for hearty play (with words) is often a forerunner of future work (for example with ideas). Yes, some take pun seriously . . .

Koponen, Maarit. 2004. Wordplay in Donald Duck Comics and Their Finnish Translations. Helsinki: Pro gradu thesis Department of English, University of Helsinki, May 2004.

Note

The three last puns are from "Funniest Puns and Jokes (Pun of the Day)" (passim). PunoftheDay.com. Accessed 8 Oct 2011. ⍽▢⍽ I like it.