Stanley, Joyce, 1901-, author
Warren, Gorham and Lamont, 1971
Buku Teks
Prentice-Hall, 1976
Buku Teks
Chommie, John C., author
West Publishing, 1968
Buku Teks
Beattie, C. N., author
Stevens & Sons Lim. , 1957
Buku Teks
technical editors, Pok Soy Yoong, Ng Keat Seng, Steven M. Timms
Lexis Nexis, 2011
Buku Referensi