Blair, Walter, author
Scott-Foresman, 1946-1947
Buku Teks
Edmundson, Mark, author
Cambridge University Press, 2011
eBooks
Monteiro, George, author
University of Kentucky Press, 1996
Buku Teks
Appleton-Century-Crofts, 1968
Buku Teks
Gultom, Samuel, author
Greenwood Press, 1987
Buku Referensi