Ritter-Sanders Jr, Miles, author
Reston Publishing , 1977
Buku Referensi
Douglas-Young, John, author
Parker Publishing Company, 1979
Buku Referensi
Middleton, Robert Gordon, 1908-, author
Reston Publishing, 1970
Buku Referensi
Craig, Edwin C., author
Springer-Verlag, 1993
Buku Teks
Douglas-Young, John
Parker Publishing Company, 1979
Buku Referensi