Greenwood, Susan, author
Berg, 2000
Buku Teks
Hoebel, E. Adamson, author
McGraw-Hill, 1966
Buku Teks
Oliver, Chad
Harper & Row , 1981
Buku Teks
Chambers, Erve, author
Waveland Press, 1989
Buku Teks
Regna Darnell dan Frederci W. Gleach
university of Nebraska Press, 2006
Buku Teks