* '''CPN Tools Homepage'''
 http://wiki.daimi.au.dk/cpntools/cpntools.wiki
 This hompage introduce Definition, function, variety example  of  CPN  Tools.

 * '''Petri-Net Definition'''
 http://en.wikipedia.org/wiki/Petri_net

 * '''CPN ML'''
 http://wiki.daimi.au.dk/cpntools-help/cpn_ml.wiki
 CPN ML(Markup Language) homepage describes Manual(declaration, Multi-sets,  Inscriptions and Expressions, Run-time Environment, State Space Functions, Monitoring Functions, etc.) of   CPN  ML.