@article{GDZPPN002079917,
title = {Triangle inequalities from the triangle inequality.},
journal = {Elemente der Mathematik},
volume = {34},
year = {1979},
pages = {49-55},
zbl = {0399.51012},
url = {http://dml.mathdoc.fr/item/GDZPPN002079917}
}
Klamkin, M.S. Triangle inequalities from the triangle inequality.. Elemente der Mathematik, Tome 34 (1979) pp. 49-55. http://gdmltest.u-ga.fr/item/GDZPPN002079917/