Painter, William H.
Little,Brown and Company, 1971
Buku Teks
Butters, J. Keith
Harvard University Press , 1951
Buku Teks
Goode, Richard
John Wiley & Sons, 1951
Buku Teks
Hale, Lloyd S.
John Wiley & Sons, 1981
Buku Teks
Tillinghast, David R.
Matthew Bender, 1984
Buku Teks