@article{MASLO_1996_46_4_a2,
     author = {Gudder, Stanley P. and Greechie, Richard},
     title = {Effect algebra counterexamples},
     journal = {Mathematica slovaca},
     pages = {317--325},
     year = {1996},
     volume = {46},
     number = {4},
     mrnumber = {1472626},
     zbl = {0890.03035},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/MASLO_1996_46_4_a2/}
}