Robertson, Silvia
Hodder & Stoughton, 1994
Buku Teks
Henschel, Astrid
Passport Books , 1994
Buku Teks
Weston, Marie-Therese
NTC Publishing Group, 1994
Buku Teks
Dina, author
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 1999
UI - Skripsi Membership
McKaughan, Howard P., author
Institute of National Language, 1958
Buku Teks