Laurel, Jose P., author
Lyceum Press, 1966
Buku Referensi
Library of Congress, Cataloging Distribution Service, 1997
Buku Referensi
The World Publishing Co., 1951
Buku Referensi
Douglas M. Considine, editor; Glenn D. Considine, managing editor
Van Nostrand Reinhold, 1989
Buku Referensi
Curzon, L. B.
CavendishPublishing Limited, 1992
Buku Teks