Mulvaney, Robert J., author
Essex Pearson, 2014
Buku Teks
editor, James A. Gould
Charles E. Merrill , 1971
Buku Teks
edited by James A. Gould
Merril Publishing, 1989
Buku Referensi
Barnes, Winston H. F., author
Adam & Charles Black, 1950
Buku Teks
Langer, Susanne K., author
John Hopkins Press, 1964
Buku Teks