J. W. A. und Kleppe, The Object Constraint Language: Getting Your Models Ready for MDA, 2 ed., Addison-Wesley Professional, 2003.
@book{kleppeocl,
author = {Jos Warmer und Anneke Kleppe},
edition = {2},
isbn = {978-0321179364},
publisher = {Addison-Wesley Professional},
title = {{The Object Constraint Language: Getting Your Models Ready for MDA}},
year = {2003}
}
OMG, About the Object Constraint Language Specification Version 2.4, 2014.
@misc{oclwebsite,
author = {OMG},
title={{About the Object Constraint Language Specification Version 2.4}},
note={\url{https://www.omg.org/spec/OCL/About-OCL/},
accessed 2019-04-04},
year = {2014},