@article{AA_2001_13_6_a4,
     author = {B. N. Khabibullin},
     title = {Excess of systems of exponentials in a~domain, and directional convexity deficiency of a~curve},
     journal = {Algebra i analiz},
     pages = {193--236},
     year = {2001},
     volume = {13},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AA_2001_13_6_a4/}
}