general editor, Sir Lawrence Gowing
Encyclopaedia Britannica, 2005
Buku Referensi
Rourke Publishing LLC, 2009
Buku Referensi
Press, Frank, author
W H Freeman , 1974
Buku Teks
edited by David A. Leeming, Kathryn Madden, Stanton Marlan
Springer, 2009
Buku Referensi
Field Enterprises Educational Corporation, 1963
Buku Referensi