Mark Leikin
Springer, 2012
eBooks
Lambert, Wallace E., author
Stanford University press, 1972
Buku Teks SO
edited by Oscar Uribe-Villegas
Mouton, 1977
Buku Teks
edited by Howard Giles and W. Peter Robinson
John Wiley & Sons, 1990
Buku Referensi
Pavlenko, Aneta, author
Cambridge University Press, 2007
Buku Teks