Voir la notice de l'article provenant de la source Math-Net.Ru
@article{TRSPY_1984_166_a14, author = {S. P. Novikov}, title = {Critical points and level surfaces of multivalued functions}, journal = {Informatics and Automation}, pages = {201--209}, publisher = {mathdoc}, volume = {166}, year = {1984}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/TRSPY_1984_166_a14/} }
S. P. Novikov. Critical points and level surfaces of multivalued functions. Informatics and Automation, Modern problems of mathematics. Differential equations, mathematical analysis and their applications, Tome 166 (1984), pp. 201-209. http://geodesic.mathdoc.fr/item/TRSPY_1984_166_a14/