@article{PA_2008_15_a1,
     author = {M. Dorff and J. Szynal},
     title = {Higher order schwarzian derivatives for convex univalent functios},
     journal = {Problemy analiza},
     pages = {7--11},
     publisher = {mathdoc},
     number = {15},
     year = {2008},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PA_2008_15_a1/}
}