Baka, Farida, author
Janus Publishing , 1988
Buku Teks
Vox, author
McGraw-Hill, 2012
Buku Referensi
Cadena, Mariano Velazquez de la, author
Follett, 1962
Buku Referensi
Cuyas, Arturo, author
Appleton-Century-Crofts, 1962
Buku Referensi
Williams, Edwin B., author
Holt, Rinehart and Winston, [Date of publication not identified]
Buku Referensi