@article{urn:eudml:doc:43471, title = {On symmetric partial derivatives an symmetric differentiability.}, journal = {Gaceta Matem\'atica}, volume = {25}, year = {1973}, pages = {100-106}, zbl = {0265.26007}, language = {en}, url = {http://dml.mathdoc.fr/item/urn:eudml:doc:43471} }
Colvin, Sam; Debnath, Lokenath. On symmetric partial derivatives an symmetric differentiability.. Gaceta Matemática, Tome 25 (1973) pp. 100-106. http://gdmltest.u-ga.fr/item/urn:eudml:doc:43471/