Commons, John R.
Macmillan, 1956
Buku Teks
Perlman, Richard, author
Dryden Press, 1972
Buku Teks
Bach, George Leland, author
Prentice-Hall, 1980
Buku Teks
Bach, George Leland, author
Prentice-Hall, 1968
Buku Teks
Bach, George Leland, author
Prentice-Hall, 1958
Buku Teks