Rothberg, Robert R., author
The Free Press, 1981
Buku Teks
Wheelwright, Steven C., author
The Free Press, 1992
Buku Teks
Weber, John A., author
Reston, 1976
Buku Teks
Siegel, Eric S.
John Wiley & Sons, 1987
Buku Teks
Donnelly, Thomas C.
The University of Mexico Press, 1953
Buku Teks