On English Handbooks
"The definition of handbooks as referential reveals a peculiarity of the genre: these are texts written to be used rather than read. And matching the fact that handbooks have no reader per se is the fact that they also, in a sense, have no authors." p. 112
"An effect of the readerless, authorless, and seemingly refereential nature of handbooks is that we tend to see them as bascailly interchangeable." p. 112
Segal, Judy Z. (1995). Textbooks and subtexts or how to choose a handbook. Journal of Teaching Writing, 14(1&2), 111-127.
She also gives some other references of interest:
Connors, Robert (1983). Handbooks: History of a genre. Rhetoric Society Quarterly, 12, 87-98.
Mayers, Walter E. (1971). Handbooks, subhandbooks, and nonhandbooks: Texts for Freshman English. College English, 32, 716-724.
Shramek, Dennis. (1992). Textbooks in Focus: Handbooks. College Composition and Communication, 43, 272-276.