1. Andonov, V., Atanassov, K.: Generalized nets with characteristics of the places. Compt. Rend. Acad. Bulg. Sci. 66(12), 1673–1680 (2013)
2. Atanassov, K.: On Generalized Nets Theory. Prof. M. Drinov Academic Publ. House, Sofia (2007)
3. Atanassov, K.: Applications of Generalized Nets. World Scientific Publ. Co., Singapore (1993)
4. Atanassova, V.: Generalized nets with volumetric tokens. Compt. rend. Acad. bulg. Sci. 65(11), 1489–1498 (2012)
5. Robinson, S., Brooks, B., Kotiadis, K., Van Der Zee, D.: Conceptual Modeling for Discrete-Event Simulation, 527 pages. Taylor and Francis Group, LLC, CRC Press (2011). ISBN-13: 978-1-4398-1038-5 (Ebook-PDF)