@article{SM_1999_190_3_a1,
     author = {E. A. Kudryavtseva},
     title = {Realization of smooth functions on surfaces as height functions},
     journal = {Sbornik. Mathematics},
     pages = {349--405},
     publisher = {mathdoc},
     volume = {190},
     number = {3},
     year = {1999},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1999_190_3_a1/}
}