@article{SF_1980__20_134420,
     author = {K. Sikdar},
     title = {On quasi-transitive semigroup actions.},
     journal = {Semigroup forum},
     pages = {269--280},
     publisher = {mathdoc},
     volume = {20},
     year = {1980},
     zbl = {0435.22004},
     url = {http://geodesic.mathdoc.fr/item/SF_1980__20_134420/}
}