@article{JRAM_1973__259_151298,
     author = {Robin Brooks},
     title = {On the sharpness of the ... 2 and ... 1 {Nielsen} numbers.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {101--108},
     year = {1973},
     volume = {259},
     zbl = {0273.55011},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1973__259_151298/}
}