Free Dashboard UI Elements PSD
Free Dashboard UI Elements PSD is a free UI Kit design resource made by Dribbble user Craftwork. As far as I can tell, its license is Creative Commons Attribution-NonCommercial-Share Alike 3.0.
Helpful hint: Dribbble users are nice. If the license is unknown, it is usually because they forgot to mention it explicitly; not because they were being stingy. Ask nicely and they will probably allow you to use it.