Gaya APA

Bettinger, A, K., A., I, H, G, A, I, E, J. (1968). **A modern approach to algebra and trigonometry . Pennsylvania: Pennsylvania: International Textbook; 1968..

Gaya MLA

Bettinger, Alvin, K.., A., I., Hutchison,, Gerald, A., II., Englund,, John. "**A modern approach to algebra and trigonometry". Pennsylvania: Pennsylvania: International Textbook; 1968., 1968. Text.