Barnes, Winston H. F., author
Adam & Charles Black, 1950
Buku Teks
Langer, Susanne K., author
John Hopkins Press, 1964
Buku Teks
Mulvaney, Robert J., author
Essex Pearson, 2014
Buku Teks
editor, James A. Gould
Charles E. Merrill , 1971
Buku Teks
Pojman, Louis P., author
Thomson Wadsworth, 2006
Buku Teks