@workingPaper{DerouetNolteRohdeZiegler_1999,
title={Oral sildenafil (VIAGRA) in Non-responders to cavernous injection therapy},
author={Derouet, Harry and Nolte, Birgit and Rohde, Volker and Ziegler, Manfred},
doi={http://dx.doi.org/10.22028/D291-20722},
year={1999}
}