Andrzej S. Murawski. Functions with local state: Regularity and undecidability. Theoretical Computer Science, 338(1-3):315-349, 2005. [doi]
@article{Murawski05:1,
title = {Functions with local state: Regularity and undecidability},
author = {Andrzej S. Murawski},
year = {2005},
doi = {10.1016/j.tcs.2004.12.036},
url = {http://dx.doi.org/10.1016/j.tcs.2004.12.036},
researchr = {https://researchr.org/publication/Murawski05%3A1},
cites = {0},
citedby = {0},
journal = {Theoretical Computer Science},
volume = {338},
number = {1-3},
pages = {315-349},
}