A few modifications to the data/*.tex files.

Corrected an error cross references, and fixed an outdated link.

Before:
![before](https://cloud.githubusercontent.com/assets/2830900/4731563/f07baa3c-59ef-11e4-8fdf-2a14d7866826.png)

After:
![after](https://cloud.githubusercontent.com/assets/2830900/4731571/fd749ee2-59ef-11e4-896e-6f51aa791b16.png)