http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Constraining designs for syntheis and timing analysis
a practical guide to synopsys design constraints (SDC)
Sridhar Gangadharan, Sanjay Churiwala ; with Chapter 17 contributed by Frederic Revenu.
Constraint programming (Computer science)