You want to find rings having some properties but not having other properties? Go there: Database of Ring Theory! A great repository of rings, their properties, and more ring theory stuff.

# Links

# Counterexamples to theorems on Clifford algebras

This page provides **counterexamples** on Clifford algebras, spinors, spin groups and the exterior algebra. You’ll find a list of counterexamples references at the end of the article.

# Link to \(\pi\)-Base

Look at pi-Base for a gold mine of topological examples.

# Wikipedia Counterexample definition

Want to know more about **counterexample** definition? Look at Wikipedia.