Darko Veljan. Problem 11116. The American Mathematical Monthly, 111(9):823, 2004. [doi]
@article{Veljan04a, title = {Problem 11116}, author = {Darko Veljan}, year = {2004}, url = {http://www.jstor.org/stable/4145202}, researchr = {https://researchr.org/publication/Veljan04a}, cites = {0}, citedby = {0}, journal = {The American Mathematical Monthly}, volume = {111}, number = {9}, pages = {823}, }