@article{AIHPB_1981__17_2_147_0,
     author = {Nualart, D. and Sanz, M.},
     title = {Changing time for two-parameter strong martingales},
     journal = {Annales de l'institut Henri Poincar\'e. Section B. Calcul des probabilit\'es et statistiques},
     pages = {147--163},
     publisher = {Gauthier-Villars},
     volume = {17},
     number = {2},
     year = {1981},
     mrnumber = {625336},
     zbl = {0463.60040},
     language = {en},
     url = {http://archive.numdam.org/item/AIHPB_1981__17_2_147_0/}
}