APA (7th ed.) Citation

NATEROP, Haberfellner, E., & Weis, E. (1977). Business letters for all. Fajar Bakti.

Chicago Style (17th ed.) Citation

NATEROP, Eva Haberfellner, and Erich Weis. Business Letters for All. Kuala Lumpur: Fajar Bakti, 1977.

MLA (9th ed.) Citation

NATEROP, et al. Business Letters for All. Fajar Bakti, 1977.