@article{10_1017_S0017089500003049,
     author = {Erdos, J. A.},
     title = {On {Boolean} algebras of projections},
     journal = {Glasgow mathematical journal},
     pages = {69--72},
     year = {1977},
     volume = {18},
     number = {1},
     doi = {10.1017/S0017089500003049},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500003049/}
}