http://www.site.uottawa.ca:4321/oose/index.html#proceduralabstraction
http://www.vocabulary.com/dictionary/abstract+entity
http://legal-dictionary.thefreedictionary.com/Abstract+entity
http://serviceorientation.com/soaglossary/entity_abstraction
http://serviceorientation.com/soaglossary/entity_abstraction
http://www.servicetechbooks.com/patterns/
http://en.wikipedia.org/wiki/Entity_Abstraction_Pattern
http://www.visual-arts-cork.com/abstract-art.htm
http://thevirtualinstructor.com/types-of-art.html
http://www.seas.upenn.edu/~sweirich/papers/popl163af-weirich.pdf
http://www.cse.chalmers.se/edu/year/2010/course/DAT140_Types/Reynolds_typesabpara.pdf
http://minds.wisconsin.edu/handle/1793/65300
http://www.etymonline.com/index.php?term=parameter
http://www.di.ens.fr/~cousot/COUSOTtalks/NSAD05.shtml
http://www.desy.de/gna/html/cc/Tutorial/node4.html