@article{GDZPPN002231395, title = {The Singular Set of an energy minimzing map from B4 to S2.}, journal = {Manuscripta mathematica}, volume = {67}, year = {1990}, pages = {275-290}, zbl = {0713.58006}, url = {http://dml.mathdoc.fr/item/GDZPPN002231395} }
Hardt, Robert; Lin, Fang-Hua. The Singular Set of an energy minimzing map from B4 to S2.. Manuscripta mathematica, Tome 67 (1990) pp. 275-290. http://gdmltest.u-ga.fr/item/GDZPPN002231395/