@article{PIM_1977_N_S_22_36_a31,
     author = {N. G. Sasha and K. C. Ray},
     title = {On {Sets} {Under} {Certain} {Transformations} {In} {RN}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {237 },
     publisher = {mathdoc},
     volume = {_N_S_22},
     number = {36},
     year = {1977},
     url = {http://geodesic.mathdoc.fr/item/PIM_1977_N_S_22_36_a31/}
}