I have already written about how to compact lists earlier today. Now is the time to compact the bibliography… This is how the regular bibliography in LaTeX looks like:

First I found a suggestion to use the setspace function, but it turns out that it is much easier to just use the bibsep option to natbib. Just add the following to the preamble:

\usepackage{natbib}
\setlength{\bibsep}{0.0pt}

and you will get something like this: