edited by Clark Tibbitts and Wilma Donahue
Prentice-Hall, 1960
Buku Teks
McNeill, Patrick, author
Macmillan, 1991
Buku Teks
Parkin, Raleigh
Green & Company, Canada, 1945
Buku Teks
Powell, G. Bingham, author
Pearson Education, 2015
Buku Teks
Rienow, Robert
D.C.Heath and Company, 1958
Buku Teks