Elkins, David E., author
Focal Press , 1993
Buku Referensi
Beaver, Frank E., author
Twayne Publishers, 1994
Buku Referensi
Phelps, Guy
Victor Gollanez, 1975
Buku Teks
Budi Irawanto, author
Media Pressindo, 1999
Buku Teks
Phelps, Guy
Victor Gollanez, 1975
Buku Teks