@article{CM_1973__26_3_283_0,
     author = {Ellentuck, Erik},
     title = {On the form of functions which preserve regressive isols},
     journal = {Compositio Mathematica},
     pages = {283--302},
     publisher = {Noordhoff International Publishing},
     volume = {26},
     number = {3},
     year = {1973},
     mrnumber = {344102},
     zbl = {0272.02067},
     language = {en},
     url = {http://www.numdam.org/item/CM_1973__26_3_283_0/}
}