North, Douglass C.
Harper & Row, 1971
Buku Teks
Clarkson, Kenneth W.
McGraw-Hill , 1982
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