http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
third edition for X11, release 4 and release 5
3rd ed., Repr. June 1993 with minor corrections.
xiii, 900 pages : illustrations ; 25 cm.
Appendix H added which notates the changes between X11, release 4 and release 5.
Definitive guides to the X Window System ; v. 4