@article{GDZPPN002157632, title = {On the addition of the double ...-functions.}, journal = {Journal f\"ur die reine und angewandte Mathematik}, volume = {88}, year = {1879}, pages = {74-81}, zbl = {11.0322.03}, url = {http://dml.mathdoc.fr/item/GDZPPN002157632} }
Cayley, A. On the addition of the double ...-functions.. Journal für die reine und angewandte Mathematik, Tome 88 (1879) pp. 74-81. http://gdmltest.u-ga.fr/item/GDZPPN002157632/