Turk, Austin T.
Sage, 1982
Buku Teks
Tec, Nechama, author
Oxford University Press, 2009
Buku Teks
Ranney, Austin, author
Holt, Rinehart and Winston , 1958
Buku Teks
Ranney, Austin
Prentice Hal, 1993
Buku Teks
Austin, Erik W.
Columbia University Press, 1986
Buku Teks