Otero, George G., author
University of Denver, 1981
Buku Teks
Malthus, Thomas
Oxford University Press, 1993
Buku Teks
Gulati, P., author
Tata McGraw-Hill, 1984
Buku Teks
Zopf, Paul E., author
Mayfield Publishing, 1984
Buku Teks
Weeks, John R. (John Robert), 1944-, author
Cengage Learning, 2016
Buku Teks