\documentclass{book}
    \usepackage{showkeys}
\usepackage{amsthm}
\usepackage{epsfig}
\usepackage{alltt}
\usepackage{young}
\usepackage{makeidx}
\usepackage{newlfont}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsxtra}
\usepackage{amsfonts}     
\usepackage{amscd}
\usepackage{mathrsfs}
\usepackage{stmaryrd}
\usepackage[ngerman]{babel}
\usepackage[hypertex,hyperindex]{hyperref}
\input{newcommands}
    \begin{document}

    \nocite{*}

    %\bibliographystyle{halpha}
    \bibliographystyle{amsalpha}
    \bibliography{pub}

    \end{document}