Robinson, Colin, author
Nelson, 1971
Buku Teks
Kahn, Herman, author
Morrow Quill Paperbacks, 1979
Buku Teks
Wheelwright, Steven C., author
John Wiley & Sons, 1980
Buku Teks
Bassie, V. Lewis
McGraw-Hill Book Company, Inc , 1958
Buku Teks
Theil, H., author
North-Holland Publishing, 1975
Buku Teks