Neumayer, Eric
Cambridge University Press, 2017
eBooks
Myers, Jerome L.
Routledge, 2010
Buku Teks
Merrill, Ray M.
Jones & Bartlett Learning, 2016
Buku Teks
Armitage, P.
Blackwell Scientific Publication, 1985
Buku Teks
Fisher, Ronald A.
Hafner Press, 1970
Buku Teks