Edward R. Scheinerman. When Close Enough is Close Enough. The American Mathematical Monthly, 107(6):489-499, 2000. [doi]
@article{Scheinerman00, title = {When Close Enough is Close Enough}, author = {Edward R. Scheinerman}, year = {2000}, url = {http://www.jstor.org/stable/2589344}, researchr = {https://researchr.org/publication/Scheinerman00}, cites = {0}, citedby = {0}, journal = {The American Mathematical Monthly}, volume = {107}, number = {6}, pages = {489-499}, }