Kranz, Rachel
Factsts On File, Inc, 2005
Buku Teks
Buku Teks
Hartman, Philip E.
Prentice Hall of India Private Limited, 1972
Buku Referensi
Learned, Edmund P. (Edmund Philip), 1900-1991
Harvard University Press, 1951
Buku Teks
Learned, Edmund P. (Edmund Philip), 1900-1991
Andover Press, 1957
Buku Teks