APA (7e ed.) Bronvermelding

JOHNSTON, C. L., WILLIS, A. T., & HUGHES, G. M. (1984). Essential arithmetic.-- ed. 4. Wadsworth Pub. Co.

Chicago (17e ed.) Bronvermelding

JOHNSTON, C. L., Alden T. WILLIS, en Gale M. HUGHES. Essential Arithmetic.-- Ed. 4. Belmont: Wadsworth Pub. Co, 1984.

MLA (9e ed.) Bronvermelding

JOHNSTON, C. L., et al. Essential Arithmetic.-- Ed. 4. Wadsworth Pub. Co, 1984.