Engelenhoven, Thomas Pieter Gerrit van
Leti: a language of southwest Maluku
KITLV Press, 2004
 Buku Teks SO
Ashikaga, Ensho
Intermediate Japanese selection from the naganuma readers, book II - IV with Kanji, vocabulary and notes
University of California Press, 1946
 Buku Teks SO
Ikeda, Tadashi
Classical Japanese grammar, illustrated with texts
Institute of Eastern Culture, 1975
 Buku Teks SO
Teng, Ssu-Yu
Conversational Chinese with grammatical notes
University of Chicago Press, 1947
 Buku Teks
Linguistic representation of english vocabulary attrition
 Artikel Jurnal