Xia, Y., Zhang, X., Luo, X. and Zhu, Q. 2013. Modelling of Ontology-based Service Compositions using Petri Net. Elektronika ir Elektrotechnika. 19, 2 (Feb. 2013), 75-78. DOI:https://doi.org/10.5755/j01.eee.19.2.3474.