Cita APA (7a ed.)

Williams, O. F. Commercial arithmetic / by Oscar F. Williams, A. M.

Cita Chicago Style (17a ed.)

Williams, Oscar F. Commercial Arithmetic / by Oscar F. Williams, A. M. New York ; Cincinnati ; Chicago : American Book Company, s.a.

Cita MLA (8a ed.)

Williams, Oscar F. Commercial Arithmetic / by Oscar F. Williams, A. M.