Himes, Joseph S.
Scott, Foresman and Company , 1968
Buku Teks
Hunt, Elgin F., author
Macmillan, 1962
Buku Teks
Owen, Robert
J.M. Dent & Sons , 1949
Buku Teks
Tippet, L.H.C.
Oxford University Press, 1950
Buku Teks
edited by Fritz Morstein Marx
Prentice-Hall, 1952
Buku Teks