APA

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

Chicago

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

Harvard

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

MLA

Williams Oscar F, .New York ; Cincinnati ; Chicago : American Book Company, s.a: . .