APA (7e ed.) Bronvermelding

Packard, S. S., & Horton, B. (1887). The new Packard commercial arithmetic. S.S. Packard.

Chicago (17e ed.) Bronvermelding

Packard, S. S., en Byron Horton. The New Packard Commercial Arithmetic. New York: S.S. Packard, 1887.

MLA (8e ed.) Bronvermelding

Packard, S. S., en Byron Horton. The New Packard Commercial Arithmetic. S.S. Packard, 1887.