Gerritse, Karl
Veen, 1991
Buku Teks
Twining, William, author
Cambridge University Press, 2012
Buku Teks
Peason, Karl
Meridian Books , 1957
Buku Teks
Soerjono Soekanto, author
Rajawali, 1985
Buku Teks
edited by John K. Ryan
The Catholic University of America Press, 1963
Buku Teks