edited by Susan Wright
Routledge, 1997
Buku Teks
Ariyono Suyono
Akademika Pressindo, 1985
Buku Teks
Beals, Ralph L
Macmillan, 1954
Buku Teks
by William A Haviland [and others]
Wadsworth and Cengage Learning, 2013
Buku Teks
editor, Maggie Toy
Academy Group, 1996
Buku Referensi