Appleby, Doris
McGraw-Hill, 1991
Buku Teks SO
Jhon Wiley & Sons , 1991
Buku Teks SO
Cherry, Edith
John Wiley & Sons, 1999
Buku Teks
Gorrell, Paul. author
Cambridge University Press, 2006
Buku Teks
Koeneman, Olaf
Cambridge University Press, 2017
Buku Teks