@article{SF_1984__28_134654,
     author = {J.W. Hogan},
     title = {The a-bicyclic semigroup as a topological semigroup.},
     journal = {Semigroup forum},
     pages = {265--272},
     publisher = {mathdoc},
     volume = {28},
     year = {1984},
     zbl = {0531.22003},
     url = {http://geodesic.mathdoc.fr/item/SF_1984__28_134654/}
}