Rocco De Nicola, Anna Labella. Nondeterministic regular expressions as solutions of equational systems. Theoretical Computer Science, 302(1-3):179-189, 2003. [doi]
@article{NicolaL03,
title = {Nondeterministic regular expressions as solutions of equational systems},
author = {Rocco De Nicola and Anna Labella},
year = {2003},
doi = {10.1016/S0304-3975(02)00774-0},
url = {http://dx.doi.org/10.1016/S0304-3975(02)00774-0},
researchr = {https://researchr.org/publication/NicolaL03},
cites = {0},
citedby = {0},
journal = {Theoretical Computer Science},
volume = {302},
number = {1-3},
pages = {179-189},
}