@article{10_4064_sm_99_2_109_113,
     author = {Masato Kikuchi},
     title = {Improved ratio inequalities for martingales},
     journal = {Studia Mathematica},
     pages = {109--113},
     publisher = {mathdoc},
     volume = {99},
     number = {2},
     year = {1991},
     doi = {10.4064/sm-99-2-109-113},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-99-2-109-113/}
}