@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/