@article{10_1017_S2040618500033086,
     author = {Ellis, David},
     title = {On {Infinite} {Series} of {Sets}},
     journal = {Glasgow mathematical journal},
     pages = {89--92},
     year = {1954},
     volume = {2},
     number = {2},
     doi = {10.1017/S2040618500033086},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S2040618500033086/}
}