@article{IM2_2005_69_6_a2,
     author = {G. E. Ivanov},
     title = {Weak convexity in the senses of {Vial} and {Efimov{\textendash}Stechkin}},
     journal = {Izvestiya. Mathematics},
     pages = {1113--1135},
     year = {2005},
     volume = {69},
     number = {6},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2005_69_6_a2/}
}