8.5.1 The thebibliography environment

In this standard L^ATEX environment, each reference is specified using a \bibitem command as:
\bibitem{key} bibliographic reference
Within the text we then may then cite this reference using the \cite{key} command. The following example shows the general L^ATEX syntax:

    \begin{thebibliography}{}
    \bibitem{ano05}
        A. Nonymous et al.\ 2005, \aap 123, 456\\[-20pt]
    \bibitem{oe04}
        A.N. Other \& S.O.M. Ebody 2004, \pasp 123, 456\\[-20pt]
    \end{thebibliography}

Any characters placed within the empty pair of brackets in \begin{thebibliography}{} will define the width of the column of numbers in the list of references. Entering 99 will suffice for any two-digit number of references. The actual citation mark that will be typeset within the text is the references number placed between square brackets. In the example, each line is terminated with \\[-20pt]. This is optional, but allows one to reduce the vertical distance between the references when the available space is limited.