La Londe, William S.
New York: McGraw-Hill, 1991
Buku Teks
Elonka, Stephen Michael
McGraw-Hill, 1981
Buku Referensi
Elonka, Stephen Michael, author
McGraw-Hill, 1981
Buku Referensi
Artikel Jurnal
Rojanapithayakorn, Wiwat, author
SEARO, 1999
Buku Teks