Hollington, Robin, author
Sweet & Maxwell , 2010
Buku Teks
Sanders, Thomas H.
Harvard. Univ., Press, 1951
Buku Teks
Cheeks, James E.
Dow Jones-Irwin , 1974
Buku Teks
Graham, Michael Dennis, author
American Management Association, 2008
eBooks
Brayne, Hugh, author
Blackstone Press, 1991
Buku Teks