Hi,

probiere mal:
Code:
\documentclass[a4paper]{article}
\usepackage[T1]{fontenc}
\usepackage[ngerman]{babel}
\usepackage{csquotes}
\usepackage[style=authoryear,labelnumber,defernumbers,citestyle=numeric]{biblatex}
\DefineBibliographyStrings{ngerman}{
    references = {Literaturverzeichnis}
}
\defbibenvironment{bibliography}
  {\list
     {\printtext[labelnumberwidth]{%
	\iffieldundef{shorthand}
	  {\printfield{prefixnumber}%
	   \printfield{labelnumber}}
	  {\printfield{shorthand}}}}
     {\setlength{\labelwidth}{\labelnumberwidth}%
      \setlength{\leftmargin}{\labelwidth}%
      \setlength{\labelsep}{\biblabelsep}%
      \addtolength{\leftmargin}{\labelsep}%
      \setlength{\itemsep}{\bibitemsep}%
      \setlength{\parsep}{\bibparsep}}%
      \renewcommand*{\makelabel}[1]{\hss##1}}
  {\endlist}
  {\item}
\DeclareFieldFormat{labelnumberwidth}{\mkbibbrackets{#1}}

\DeclareNameFormat{last-first}{%
  \iffirstinits
    {\usebibmacro{name:last-first}{#1}{#4}{#5}{#7}}
    {\usebibmacro{name:last-first}{#1}{#4}{#5}{#7}}%
  \usebibmacro{name:andothers}}
\DeclareNameAlias{sortname}{last-first}

\DeclareFieldFormat*{volume}{\textbf{\bibstring{volume}~#1}}
\usepackage{hyperref}
\addbibresource{biblatex-examples.bib}
\newcommand{\cmd}[1]{\texttt{\textbackslash #1}}
\begin{document}
\section*{The \texttt{numeric} style}
XXX
\subsection*{\cmd{cite} examples}
Test \cite{companion} test.
\printbibliography
\end{document}
Gruß
Marco

PS: Als Tipp: Fast alle Definitionen findest du in der biblatex.def