edited by Vicente Y. Belizario, Jr; Juan Antonio A. Solon
Johnson, 2000
Buku Teks
Cable, Raymond M., author
Burgess, 1958
Buku Teks
by Elmer R. Noble ... [and others]
Lea & Febiger, 1989
Buku Referensi
Brown, Harold W., author
Gramedia , 1983
Buku Teks
Pavlov, Alexander A., author
Peace Publishers, [date of publication not identified]
Buku Teks