Robert McNaughton, Hisao Yamada. Regular Expressions and State Graphs for Automata. IEEE Transactions on Computers, 9(1):39-47, 1960. [doi]
@article{McNaughtonY60,
title = {Regular Expressions and State Graphs for Automata},
author = {Robert McNaughton and Hisao Yamada},
year = {1960},
doi = {10.1109/TEC.1960.5221603},
url = {http://dx.doi.org/10.1109/TEC.1960.5221603},
researchr = {https://researchr.org/publication/McNaughtonY60},
cites = {0},
citedby = {0},
journal = {IEEE Transactions on Computers},
volume = {9},
number = {1},
pages = {39-47},
}