Sackheim, George I.
Macmillan, 1973
Buku Teks
Bodner, George M.
John Wiley & Sons, 1995
Buku Teks
Sackheim, George I., author
Macmillan, 1977
Buku Teks
Pimentel, George C., author
Holden-Day, 1971
Buku Teks
Oxtoby, David W., author
Thomson, Brooks/Cole, 2003
Buku Teks