@article{10_4064_cm_31_1_11_20,
     author = {B. M. Schein},
     title = {Function \ensuremath{\cup}-semigroups},
     journal = {Colloquium Mathematicum},
     pages = {11--20},
     publisher = {mathdoc},
     volume = {31},
     number = {1},
     year = {1974},
     doi = {10.4064/cm-31-1-11-20},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-31-1-11-20/}
}