@article{10_1017_S0017089500000835,
     author = {Jr, Kenneth D. Magill},
     title = {Homomorphic images of restrictive star semigroups},
     journal = {Glasgow mathematical journal},
     pages = {58--71},
     year = {1970},
     volume = {11},
     number = {1},
     doi = {10.1017/S0017089500000835},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500000835/}
}