@article{10_4153_CMB_2011_113_8,
     author = {Os\k{e}kowski, Adam},
     title = {Sharp {Inequalities} for {Differentially} {Subordinate} {Harmonic} {Functions} and {Martingales}},
     journal = {Canadian mathematical bulletin},
     pages = {597--610},
     year = {2012},
     volume = {55},
     number = {3},
     doi = {10.4153/CMB-2011-113-8},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-2011-113-8/}
}