Huntington, Ellsworth
John Wiley & Sons, 1960
Buku Teks
Malinowski, Jon C.
McGraw-Hill, 2012
Buku Teks
by Jerome D. Fellmann, Mark D. Bjelland, Arthur Getis, Judith Getis
McGraw-Hill, 2010
Buku Teks
Lebon, J. H. G.
Hutchinson University Library, 1969
Buku Teks
Getis, Arthur
Macmillan, 1985
Buku Teks