Universitas Indonesia, 2006
UI - Skripsi (Membership)
Hamburg, Morris, author
Harcourt Brace Jovanovich, Pub., 1991
Buku Teks
Diamond, Solomon
Basic Book , 1959
Buku Teks
Universitas Indonesia, 2006
UI - Skripsi (Membership)
Johnson, Richard A., author
Pearson Education International, 2007
Buku Teks