@article{SPS_1989__23__66_0,
     author = {\'Emery, Michel},
     title = {On the {Az\'ema} martingales},
     journal = {S\'eminaire de probabilit\'es de Strasbourg},
     pages = {66--87},
     publisher = {Springer - Lecture Notes in Mathematics},
     volume = {23},
     year = {1989},
     mrnumber = {1022899},
     zbl = {0753.60045},
     language = {en},
     url = {http://www.numdam.org/item/SPS_1989__23__66_0/}
}