edited by Jeyanth Asheervath and Dorothy R. Blevins
Appleton-Century-Crofts, 1986.
Buku Referensi
Smith, Sandra
Appleton & Lange , 1992
Buku Teks
Reilly, Dorothy E.
Jones and Bartlett , 1999
Buku Teks
Reilly, Dorothy E.
Appletton & Lange, 1985
Buku Teks
Martin, Colin R.
Routledge, 2000
Buku Teks SO