Gaya APA

CALLUM, G, P. (1983). Idiom Drills for studentd of english as a second language (-). New York: Harper and Row.

Gaya MLA

CALLUM, George, P.. "Idiom Drills for studentd of english as a second language". - New York: Harper and Row, 1983. Buku Pend. Bahasa Inggris.