Bibliography

X - a portable, network-transparent window system
by X Consortium, Inc.
pub by Open Software Foundation
1994
X(7)
gs - Ghostscript (PostScript and PDF language interpreter and previewer)
by L. Peter Deutsch, mailto:ghost@aladdin.com
pub by Open Software Foundation
2002
gs(1)
Designing Letter and Reply Mail
by United States Postal Service
pub by United States Postal Service
June 2003
Publication 25
http://pe.usps.gov/text/Pub25/Pub25.htm