@article{ELMA_1973__28_141125,
     author = {Murray S. Klamkin},
     title = {Two {Non-Negative} {Quadratic} {Forms.}},
     journal = {Elemente der Mathematik},
     pages = {141--146},
     publisher = {mathdoc},
     volume = {28},
     year = {1973},
     zbl = {0266.52006},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1973__28_141125/}
}