Cita APA (7th ed.)

Butler, C. H. 1., & Wren, F. L. 1. (1960). The teaching of secondary mathematics (3d ed.). McGraw-Hill.

Cita Chicago (17th ed.)

Butler, Charles H. 1894, i Frank Lynwood 1894 Wren. The Teaching of Secondary Mathematics. 3d ed. New York: McGraw-Hill, 1960.

Cita MLA (9th ed.)

Butler, Charles H. 1894, i Frank Lynwood 1894 Wren. The Teaching of Secondary Mathematics. 3d ed. McGraw-Hill, 1960.