edited ny Keith Friye
Hutchinson Ross, 1981
Buku Referensi
edited by Sybil P. Parker
McGraw-Hill, 1997
Buku Referensi
Mason, Brian, author
W.H. Freeman, 1968
Buku Teks
Blackburn, William H.
W.C. Brown Publishers, 1988
Buku Referensi
Dana, Edward Salisbury
John Wiley & Sons, 1972
Buku Teks