Chai Wah Wu. Pigeonholes and Repunits. The American Mathematical Monthly, 121(6):529-533, 2014. [doi]
@article{Wu14-44,
title = {Pigeonholes and Repunits},
author = {Chai Wah Wu},
year = {2014},
doi = {10.4169/amer.math.monthly.121.06.529},
url = {http://dx.doi.org/10.4169/amer.math.monthly.121.06.529},
researchr = {https://researchr.org/publication/Wu14-44},
cites = {0},
citedby = {0},
journal = {The American Mathematical Monthly},
volume = {121},
number = {6},
pages = {529-533},
}