@article{ELMA_1968__23_140880,
     author = {W. Sierpinski},
     title = {Un th\'eor\`eme sur les nombres triangulaires.},
     journal = {Elemente der Mathematik},
     pages = {31--32},
     publisher = {mathdoc},
     volume = {23},
     year = {1968},
     zbl = {0153.37404},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1968__23_140880/}
}