Perl, Philip.
Time-Life Books, 1979
Buku Referensi
Reinhold Publishing Corporation, 1961
Buku Teks
Syahrizal, author
2011
UI - Tesis (Open)
Goldscheider, Gaby, author
Berkshire Gaby Goldscheider, 1979
Buku Teks
McGlynn, Daniel R., author
John Wiley & Sons, 1976
Buku Teks