Johnston, R.J. (Ronald John), author
Routledge, 2016
Buku Teks
[publisher not identified], [date of publication no identified]
Buku Teks
Malinowski, Jon C., author
McGraw-Hill, 2012
Buku Teks
Getis, Arthur, author
Macmillan, 1985
Buku Teks
Lebon, J. H. G., author
Hutchinson University Library, 1969
Buku Teks