Mason, Alpheus Thomas,1899-1989
Prentice-Hall, 1964
Buku Teks
Swisher, Carl Brent
University of Chicago Press, 1946
Buku Teks SO
Ducat, Craig R.
Wardsworth Cengage Learning, 2013
Buku Teks SO
Heringa, A.W.
Metro, 2009
Buku Teks SO
Stannard, Harold
Adam and Charles Black, 1949
Buku Teks SO