Lebon, J. H. G., author
Hutchinson University Library, 1969
Buku Teks
Malinowski, Jon C., author
McGraw-Hill, 2012
Buku Teks
by Jerome D. Fellmann, Mark D. Bjelland, Arthur Getis, Judith Getis
McGraw-Hill, 2010
Buku Teks
Huntington, Ellsworth, author
John Wiley & Sons, 1951
Buku Teks
Huntington, Ellsworth, author
John Wiley & Sons, 1960
Buku Teks