Michael Becker. Problem 10919. The American Mathematical Monthly, 109(1):77-78, 2002. [doi]
@article{Becker02-0, title = {Problem 10919}, author = {Michael Becker}, year = {2002}, url = {http://www.jstor.org/stable/2695777}, researchr = {https://researchr.org/publication/Becker02-0}, cites = {0}, citedby = {0}, journal = {The American Mathematical Monthly}, volume = {109}, number = {1}, pages = {77-78}, }