@article{1077491900, author = {Morse, Marston}, title = {The first variation in minimal surface theory}, journal = {Duke Math. J.}, volume = {6}, number = {1}, year = {1940}, pages = { 263-289}, language = {en}, url = {http://dml.mathdoc.fr/item/1077491900} }
Morse, Marston. The first variation in minimal surface theory. Duke Math. J., Tome 6 (1940) no. 1, pp. 263-289. http://gdmltest.u-ga.fr/item/1077491900/