Tan, Ngoc Chau
Unesco, 1972
Buku Teks
Miro, Carmen A.
Frances Pinter Publ., 1980
Buku Teks
King, Kenneth, author
Longmann Group, 1991
Buku Teks
Gould, W.T.S., author
John Wiley, Longman Scientific, 1993
Buku Teks
edited by Keith Watson
Croom Helm, 1982
Buku Teks