Tom Bourne, Nik Ruskuc. On the star-height of subword counting languages and their relationship to Rees zero-matrix semigroups. Theoretical Computer Science, 653:87-96, 2016. [doi]
@article{BourneR16,
title = {On the star-height of subword counting languages and their relationship to Rees zero-matrix semigroups},
author = {Tom Bourne and Nik Ruskuc},
year = {2016},
doi = {10.1016/j.tcs.2016.09.024},
url = {http://dx.doi.org/10.1016/j.tcs.2016.09.024},
researchr = {https://researchr.org/publication/BourneR16},
cites = {0},
citedby = {0},
journal = {Theoretical Computer Science},
volume = {653},
pages = {87-96},
}