This thermodynamic quantity equals what?

I am trying to use thermodynamics manipulations in order to find [itex]\partial[/itex]P/[itex]\partial[/itex]V (at constant entropy) I tried replacing P by T([itex]\partial[/itex]S/[itex]\partial[/itex]V)(at constant Energy) and then differentiated that by V but didn't help me. Do you have any idea where I can get around with this? Just throw in any formula!

Thanks!