Gaya APA

Gartside, L. (1989). Model business letters : a classified selection of modern business letters for use in schools and in business (3rd ed). Jakarta: Bina Rupa Aksara.

Gaya MLA

Gartside, L.. "Model business letters : a classified selection of modern business letters for use in schools and in business". 3rd ed Jakarta: Bina Rupa Aksara, 1989. Text.