Peter McGrath. An Extremely Short Proof of the Hairy Ball Theorem. The American Mathematical Monthly, 123(5):502-503, 2016. [doi]
@article{McGrath16a,
title = {An Extremely Short Proof of the Hairy Ball Theorem},
author = {Peter McGrath},
year = {2016},
url = {https://www.tandfonline.com/doi/abs/10.4169/amer.math.monthly.123.5.502},
researchr = {https://researchr.org/publication/McGrath16a},
cites = {0},
citedby = {0},
journal = {The American Mathematical Monthly},
volume = {123},
number = {5},
pages = {502-503},
}