Farrell, Jane
J.B. Lippincott, 1986
Buku Teks
Greenspan, Adam
Wolters Kluwer, 2015
Buku Teks
Leagogo, Liberto Antonio C., editor
Information, Publication and Public Affairs Office, 1998
Buku Referensi
Information,Publication and Public affairs Office University of the Philipines Manila, 1998,
Buku Referensi
Harold, Elliotte Rusty
IDG Books Worldwide, 1997
Buku Teks