Yen, Hsu-ChunHsu-ChunYenWang, Bow-YawBow-YawWangYang, Ming-ShengMing-ShengYangHSU-CHUN YEN2020-06-162020-06-161994https://scholars.lib.ntu.edu.tw/handle/123456789/502483Some Complexity Results for Rings of Petri Nets.journal article10.1142/S0129054194000153https://doi.org/10.1142/S0129054194000153