@article{DMGAA_2003_23_1_a5,
     author = {Beltrametti, Enrico and Maczy\'nski, Maciej},
     title = {Effect algebras and ring-like structures},
     journal = {Discussiones Mathematicae. General Algebra and Applications},
     pages = {63--79},
     publisher = {mathdoc},
     volume = {23},
     number = {1},
     year = {2003},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DMGAA_2003_23_1_a5/}
}