Pili, I. B. (1977). A survey of completed descriptive and contrastive researches on teaching English as a second language from 1959 to 1971 [microform]. Photoduplication Service.University of the Philippines Library.
Chicago-referens (17:e uppl.)Pili, Irene B. A Survey of Completed Descriptive and Contrastive Researches on Teaching English as a Second Language from 1959 to 1971 [microform]. Quezon City: Photoduplication Service.University of the Philippines Library, 1977.
MLA-referens (9:e uppl.)Pili, Irene B. A Survey of Completed Descriptive and Contrastive Researches on Teaching English as a Second Language from 1959 to 1971 [microform]. Photoduplication Service.University of the Philippines Library, 1977.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.