Blumenthal, J. C. (1969). Tests for English 2600: A programed course in grammar and usage (3rd ed.). Harcourt, Brace & World.
Chicago-referens (17:e uppl.)Blumenthal, Joseph C. Tests for English 2600: A Programed Course in Grammar and Usage. 3rd ed. New York, N.Y.: Harcourt, Brace & World, 1969.
MLA-referens (8:e uppl.)Blumenthal, Joseph C. Tests for English 2600: A Programed Course in Grammar and Usage. 3rd ed. Harcourt, Brace & World, 1969.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.