@article{1183492031, author = {Weaver, J. H.}, title = {Invariants of a poristic system of triangles}, journal = {Bull. Amer. Math. Soc.}, volume = {33}, number = {6}, year = {1927}, pages = { 235-240}, language = {en}, url = {http://dml.mathdoc.fr/item/1183492031} }
Weaver, J. H. Invariants of a poristic system of triangles. Bull. Amer. Math. Soc., Tome 33 (1927) no. 6, pp. 235-240. http://gdmltest.u-ga.fr/item/1183492031/