Media Consulta, 2003
Buku Referensi
Gedes & Grosset, 2001
Buku Referensi
Ministry of culture and information, 1970
Buku Referensi
editor, Gorton Carruth
Thomas Y. Growell, 1962
Buku Referensi
Talos, Emmerich, author
Federal Perss Service, 1991
Buku Referensi