Kemp, Herman C., author
KITLV Press, 1990
Buku Referensi
Groenendael, Victoria M. Clara van, author
Foris Publications, 1987
Buku Referensi
Salmon, Claudine, author
Editions de la Maison des sciences de l'homme, 1981
Buku Referensi
United Nations Centre for Regional Development , 1983
Buku Teks
Greenwood Press, 1977
Buku Referensi