@article{SPS_1977__11__27_0,
     author = {Chung, Kai Lai},
     title = {Pedagogic notes on the barrier theorem},
     journal = {S\'eminaire de probabilit\'es de Strasbourg},
     pages = {27--33},
     publisher = {Springer - Lecture Notes in Mathematics},
     volume = {11},
     year = {1977},
     mrnumber = {445620},
     zbl = {0376.60080},
     language = {en},
     url = {http://www.numdam.org/item/SPS_1977__11__27_0/}
}