Jevon, Phil, author
John Wiley & Sons, 2014
Buku Teks
Harrison, Richard, author
Churchill Livingstone, 2011
Buku Teks
Stilp, Richard H.
Delmar Publishers, 1997
Buku Teks
by Joseph J. Mistovich
Prentice-Hall, 1998
Buku Teks
Gallup, George, author
McGraw-Hill, 1982
Buku Teks