English Languaje Services. (1964). The Key to english. Collier Macmillan.
Chicago Style (17th ed.) CitationEnglish Languaje Services. The Key to English. London: Collier Macmillan, 1964.
MLA (9th ed.) CitationEnglish Languaje Services. The Key to English. Collier Macmillan, 1964.
Warning: These citations may not always be 100% accurate.