Hiroshi Maehara. On the Total Edge-Length of a Tetrahedron. The American Mathematical Monthly, 108(10):967-969, 2001. [doi]
@article{Maehara01, title = {On the Total Edge-Length of a Tetrahedron}, author = {Hiroshi Maehara}, year = {2001}, url = {http://www.jstor.org/stable/2695418}, researchr = {https://researchr.org/publication/Maehara01}, cites = {0}, citedby = {0}, journal = {The American Mathematical Monthly}, volume = {108}, number = {10}, pages = {967-969}, }