McKay, Sandra Lee, author
Mahwah, New Jersey, 2006
Buku Teks
Ngeow Chow-Bing, editor
Routledge, Taylor & Francis Group, 2019
Buku Teks
Miguel A R B Castanho, editor
[, Springer], 2012
eBooks
Hyland, Ken, author
Longman, 2002
Buku Teks
Hartmann, Reinhard R.K., author
Pearson Education, 2001
Buku Teks