1. On formalizing uml with high-level petri nets;Baresi,2001
2. Analysis and testing of plexil plans;Biatek,2014
3. Flow diagrams, turing machines and languages with only two formation rules;Böhm;Commun. ACM,1966
4. Extending pddl for hierarchical planning and topological abstraction;Botea,2003
5. Formal refinement patterns for goal-driven requirements elaboration;Darimont,1996