Tero Harju, Dirk Nowotka. Periodicity and unbordered words: A proof of the extended duval conjecture. Journal of the ACM, 54(4):20, 2007. [doi]
@article{HarjuN07,
title = {Periodicity and unbordered words: A proof of the extended duval conjecture},
author = {Tero Harju and Dirk Nowotka},
year = {2007},
doi = {10.1145/1255443.1255448},
url = {http://doi.acm.org/10.1145/1255443.1255448},
researchr = {https://researchr.org/publication/HarjuN07},
cites = {0},
citedby = {0},
journal = {Journal of the ACM},
volume = {54},
number = {4},
pages = {20},
}