Gaya APA

Swanson, C, P., Wright, D, F. (1990). Essential mathemathics a worktext . Massachusetts: Massachusetts: D.C. Heath; 1990.

Gaya MLA

Swanson, Carl, P.., Wright, D., Franklin. "Essential mathemathics a worktext". Massachusetts: Massachusetts: D.C. Heath; 1990, 1990. Text.