Mackie, Benita, author
Upper Saddle River,N.J. Prentice Hall 1995,
Buku Teks
Cornog, Mary Wood
Springfield:Massachusetts Merriam-Webster, 1994,
Buku Teks
New York : Holt, Rinehart and Winston, 1995,
Buku Teks
Nababan, Melva Ratna Rulida, author
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 1983
UI - Skripsi (Membership)
Longman Group UK Limited , 1975
Buku Teks