@article{SM_2014_205_6_a1,
     author = {A. I. Vorob'ev},
     title = {Characterizing quasiconvex functions in terms of the {Kronrod's} tree of a~function},
     journal = {Sbornik. Mathematics},
     pages = {777--780},
     publisher = {mathdoc},
     volume = {205},
     number = {6},
     year = {2014},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2014_205_6_a1/}
}