@article{GDZPPN002192888,
title = {An annular function whose derivative is not annular.},
journal = {Journal f\"ur die reine und angewandte Mathematik},
volume = {281},
year = {1976},
pages = {146-151},
zbl = {0333.30019},
url = {http://dml.mathdoc.fr/item/GDZPPN002192888}
}
Bonar, D.D.; Barth, K. An annular function whose derivative is not annular.. Journal für die reine und angewandte Mathematik, Tome 281 (1976) pp. 146-151. http://gdmltest.u-ga.fr/item/GDZPPN002192888/