Markos, Ni
Institute of Linguistics Philippine, 1966
Buku Teks
Macarthur, J. R.
D. Appleton-Century, 1936
Buku Teks
Buck, Pearl Sydenstricker, 1892-1973, author
A. Signet Book, 1971
Buku Teks
Davis, Kenneth C., author
Perennial, 2004
Buku Teks
Cook, Stanley
Penguin Books, 1945
Buku Teks