@article{10_4153_CMB_1973_028_9,
     author = {Al-Hussaini, A. N.},
     title = {On {Characterizations} of {Conditional} {Expectation}},
     journal = {Canadian mathematical bulletin},
     pages = {161--163},
     year = {1973},
     volume = {16},
     number = {2},
     doi = {10.4153/CMB-1973-028-9},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1973-028-9/}
}