Colbert, Don, author
Siloam A Strang Company, 2007
Buku Teks
Newman, Margaret A.
C.V. Mosby, 1986
Buku Teks
editors: Benjamin Ariel Marte, Alfred Merkle, Detlef Schwefel
Chaiporn Film Partnership, 1996
Buku Referensi
compiled and edited by Elaine Cumming
Jossey-Bass, 1970
Buku Teks
Booth, Kathryn A., 1957-, author
McGraw-Hill, 2009
Buku Teks