Free Educational-themed Icons
This is an educational-themed iconset with 12 icons inside.
Free Educational-themed Icons is a free Icon design resource made by Dribbble user Georke Kvasnikov. As far as I can tell, its license is Unknown.
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.