APA (7th ed.) Zitazioa
Walvoord, B. E. (1988). Three steps to revising your writing for style, grammar, punctuation, and spelling. Scott. Foresman and Co..
Chicago Style (17th ed.) Zitazioa
Walvoord, Barbara E. Three Steps to Revising Your Writing for Style, Grammar, Punctuation, and Spelling. Clenview, Illinois: Scott. Foresman and Co., 1988.
MLA (9th ed.) Zitazioa
Walvoord, Barbara E. Three Steps to Revising Your Writing for Style, Grammar, Punctuation, and Spelling. Scott. Foresman and Co., 1988.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.