APA (7e ed.) Bronvermelding

Butler, C. H., & Wren, F. L. 1. . . j. a. (1941). The teaching of secondary mathematics. McGraw-Hill.

Chicago (17e ed.) Bronvermelding

Butler, Charles Henry, en Frank Lynwood 1894- joint auth Wren. The Teaching of Secondary Mathematics. New York: McGraw-Hill, 1941.

MLA (9e ed.) Bronvermelding

Butler, Charles Henry, en Frank Lynwood 1894- joint auth Wren. The Teaching of Secondary Mathematics. McGraw-Hill, 1941.