@article{AFM_1996_21_2_a0,
     author = {Tadeusz Iwaniec and Gaven Martin},
     title = {Quasiregular semigroups},
     journal = {Annales Fennici Mathematici},
     pages = {241--254},
     publisher = {mathdoc},
     volume = {21},
     number = {2},
     year = {1996},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AFM_1996_21_2_a0/}
}