APA aipamena

Butler, C. H. 1., & Wren, F. L. (1963). Trigonometry for secondary schools (3rd ed.). Heath.

Chicago Style aipamena

Butler, Charles H. 1894, and Frank Lynwood Wren. Trigonometry for Secondary Schools. 3rd ed. Boston: Heath, 1963.

MLA aipamena

Butler, Charles H. 1894, and Frank Lynwood Wren. Trigonometry for Secondary Schools. 3rd ed. Heath, 1963.