Ward, Robert
Philippines Summer Institute of Linguistic Translator Philippines Publishers 1968
Buku Teks
compiled by Howard P. McKaughan, Batua A. Macaraya
University of Hawaii Press, 1967
Buku Referensi
McKaughan, Howard P., author
Institute of National Language, 1958
Buku Teks
Sapir, Edward
Munchen Heuber 1961
Buku Teks
Rehbein, Jochen
Buku Teks