Writing Improvement Project. (1977). Building English skills. McDougal, Littell & Company.
Chicago-referens (17:e uppl.)Writing Improvement Project. Building English Skills. Evanston, Illinois: McDougal, Littell & Company, 1977.
MLA-referens (9:e uppl.)Writing Improvement Project. Building English Skills. McDougal, Littell & Company, 1977.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.