@article{10_4064_ba58_1_8,
     author = {Adam Os/ekowski},
     title = {Sharp {Ratio} {Inequalities} for a {Conditionally} {Symmetric} {Martingale}},
     journal = {Bulletin of the Polish Academy of Sciences. Mathematics},
     pages = {65--77},
     publisher = {mathdoc},
     volume = {58},
     number = {1},
     year = {2010},
     doi = {10.4064/ba58-1-8},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ba58-1-8/}
}