I usually have never found vertical splits to be helpful, though others may disagree. I prefer to keep several horizontal splits (in your case above). Just use

I usually have never found vertical splits to be helpful, though others may disagree. I prefer to keep several horizontal splits (in your case above). Just use C-j or C-k, your current file is maximized. Remember, you have other options too, such as tabs, and just opening aux files as buffers and C-n or C-p to get to them.