@article{RM_2011_66_4_a7,
     author = {P. A. Yaskov},
     title = {Necessary conditions in the law of large numbers for martingales and associated systems},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {822--824},
     year = {2011},
     volume = {66},
     number = {4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_2011_66_4_a7/}
}