Ingpen, Robert
Dragon's World, 1993
Buku Referensi
Franklin, Benjamin
The Spencer Press, 1936
Buku Teks
Blundell, Nigel
Octopus Books Limited, 1980
Buku Teks
Nayla Aprilia Latukau
2019
UI - Skripsi Membership
Direktorat Jendral PPG, Departemen Penerangan , 1991
Buku Teks