@misc{paul_polyacrylonitrile_membranes_1994, 
author={Paul, D.,Albrecht, W.,Weigel, T.},
title={Polyacrylonitrile membranes for ultrafiltration},
year={1994},
howpublished = {journal article},
note = {Online available at: \url{} (DOI). Paul, D.; Albrecht, W.; Weigel, T.: Polyacrylonitrile membranes for ultrafiltration. Water and waste treatment. 1994. vol. 9, no. 7, 257-264.}}