@article{PA_2017_6_2_a2,
     author = {S. Yu. Graf},
     title = {The {Schwarzian} derivatives of harmonic functions and univalence conditions},
     journal = {Problemy analiza},
     pages = {42--56},
     publisher = {mathdoc},
     volume = {6},
     number = {2},
     year = {2017},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PA_2017_6_2_a2/}
}