Explicit reference to paper and slides for improvements to measurements

It cannot hurt to reinforce the point that BenchExec
provides better measurements than other tools
by linking to our material where this is described in detail.

README.md

@@ -51,6 +51,12 @@ Linux [user namespaces](http://man7.org/linux/man-pages/man7/namespaces.7.html)
 and an [overlay filesystem](https://www.kernel.org/doc/Documentation/filesystems/overlayfs.txt)
 to create a [container](https://github.com/sosy-lab/benchexec/blob/main/doc/container.md)
 that restricts interference of the executed tool with the benchmarking host.
+More information on why this is necessary and the problems with other tools
+can be found in our paper
+[Reliable Benchmarking: Requirements and Solutions](https://doi.org/10.1007/s10009-017-0469-y) (open access)
+and our [slides](https://www.sosy-lab.org/research/prs/Latest_ReliableBenchmarking.pdf)
+(starting with slide "Checklist").
+
 BenchExec is intended for benchmarking non-interactive tools on Linux systems.
 It measures CPU time, wall time, and memory usage of a tool,
 and allows to specify limits for these resources.