Manfred Kudlek.
Multisets and Petri nets - an overview.
JCISS, 33(3-4):339-355, 2008.
@Article{Kudlek08g, author = {Kudlek, Manfred}, title = {Multisets and {Petri} Nets -- An Overview}, journal = {JCISS}, year = 2008, volume = 33, number = {3--4}, pages = {339--355} }