@article{GDZPPN001176803, title = {The Indicatrix Method in Free Boundary Problems.}, journal = {Numerische Mathematik}, volume = {39}, year = {1982}, pages = {39-52}, zbl = {0452.65068}, url = {http://dml.mathdoc.fr/item/GDZPPN001176803} }
Fage, D.M. The Indicatrix Method in Free Boundary Problems.. Numerische Mathematik, Tome 39 (1982) pp. 39-52. http://gdmltest.u-ga.fr/item/GDZPPN001176803/