biblatex und autocites-Befehl

\documentclass[ngerman]{scrartcl}

\usepackage[ansinew]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{babel}
\usepackage[autostyle]{csquotes}
\usepackage[useprefix=true,uniquename=init,sorting=nyt,firstinits=true,%
seriesformat=standard,idemfont=normal,namefont=smallcaps,%
firstnamefont=smallcaps,idembib=true,style=footnote-dw,nopublisher=false,%
backend=biber]{biblatex}
\usepackage{filecontents}

\begin{filecontents}{TestBib.bib}
@INBOOK{Andreani2006,
 pages = {15--17},
 title = {La Cappella di San Brizio e il Giudizio Universale di Luca Signorelli},
 year = {2006},
 editor = {A. Cannistrà},
 author = {Laura Andreani},
 booktitle = {Le stanze delle meraviglie},
 location = {Cinisello Balsamo},
 gender = {sf},
 shorthand = {Andreani 2006}
 }

 @BOOK{BokernGoerdueren1999,
  author = {Anneke Bokern and Petra Gördüren},
  title = {Die letzten Dinge},
  subtitle = {Jahrhundertwende und Jahrhundertende in der bildenden Kunst um 1500 und 2000},
  location = {Berlin},
  year = {1999},
  gender = {pf},
  shorthand = {Bokern/Gördüren 1999}
}
\end{filecontents}
\addbibresource{TestBib.bib}

\begin{document}
Hallo\autocite{BokernGoerdueren1999}
Hallo\autocite{BokernGoerdueren1999}
Und hier\autocites{BokernGoerdueren1999}{Andreani2006}
Und wieder\autocite{Andreani2006}
Und wieder\autocite{Andreani2006}
\printbibliography[title={Quellenverzeichnis}]
\end{document}