Reference:

J. Esparza and M. Silva. Top-down synthesis of free choice nets. In G. Rozenberg, editor, Advances in Petri Nets 1991, number 524 in Lecture Notes in Computer Science, pages 118–139, 1991.

Suggested BibTeX entry:

@inproceedings{ES91a,
    author = {J. Esparza and M. Silva},
    booktitle = {Advances in {P}etri Nets 1991},
    editor = {G.~Rozenberg},
    number = {524},
    pages = {118--139},
    series = {Lecture Notes in Computer Science},
    title = {Top-Down Synthesis of Free Choice Nets},
    year = {1991}
}