Mashaw, Jerry l.
St. Paul Minn, 1975
Buku Teks
Friedman, Lawrence M., 1930-
Tatanusa, 2001
Buku Teks
Graber, Mark A.
Oxford University Press, 2015
Buku Teks
Poe, Jerry B.
Richard D. Irwin, 1974
Buku Teks
Poe, Jerry B.
Richard D. Irwin, 1986
Buku Teks