Gaya APA

maggs, M. (1978). Programmed English : A self-instructional course . the United States of America: [s.l].Grolier International. Inc.

Gaya MLA

maggs, Margaret. "Programmed English : A self-instructional course". the United States of America: [s.l].Grolier International. Inc, 1978. Koleksi Elektronik.