Boulding, Kenneth E. (Kenneth Ewart), 1910-1993, author
Beverly Hull, 1985
Buku Teks
Lenski, Gerhard, author
McGraw-Hill , 1992
Buku Teks
edited by Edward H. Spicer
Russell Sage Foundation, 1952
Buku Teks
Diamond, Jared, author
Norton, 2005
Buku Teks
Ruse, Michael, author
Cambridge University Press, 2012
Buku Teks