Santiago, Francisco
University of the Philippines, 1957
Buku Teks SO
Foreman, John
T. Fisher Unwin , 1906
Buku Teks SO
Stow, Randolph, 1935-2010
Pan Books, 1982
Buku Teks SO
Francisco, Juan R.
Linguistic Society of The Philippines, 1973
Buku Teks SO
Reyess, Elizabeth
Tuttle Publishing, 2012.
Buku Teks SO