Jerry Lodder. Curvature in the Calculus Curriculum. The American Mathematical Monthly, 110(7):593-605, 2003. [doi]
@article{Lodder03, title = {Curvature in the Calculus Curriculum}, author = {Jerry Lodder}, year = {2003}, url = {http://www.jstor.org/stable/3647744}, researchr = {https://researchr.org/publication/Lodder03}, cites = {0}, citedby = {0}, journal = {The American Mathematical Monthly}, volume = {110}, number = {7}, pages = {593-605}, }