Poh Chu Chai
Longman, 199
Buku Teks
Sloan, Irving J.
Ocean Publications, 1988
Buku Teks
Callahan, Parnell Joseph Terence
Oceana Publications, 1970
Buku Teks
Browne, Ray B., author
Bowling Green State University, 1986
Buku Teks
Cheeseman, Henry R., author
Prentice-Hall, 1998
Buku Teks