Koen Vermeir
Springer, 2012
eBooks
Charles W. Eliot, edited
P. F. Collier & Son Corporation, 1959 ; 1969
Buku Referensi
edited by Evelyn G. Pike and Rachel Saint
Summer Institute of Linguistics, 1989
Buku Teks SO
Robson, L.L.
Cambridge University Press, 1976
Buku Teks
Lacour, Claudia Brodsky
Duke University Press, 1996
Buku Teks SO