Here's How Mazda Built its Rotary Engine (article) by Raphael Orlove

This was a very interesting article, because I didn't know a lot about rotary engines beforehand, and this gives insight into Mazda's innovation and how they were able to apply that tech to their sometimes very fuel-efficient vehicles, or extremely powerful vehicles that dominated the import JDM racing scene and gave way to a revolution.  The author, Raphael Orlove, is able to find a way to convey the message and information of rotary engines in a fun and descriptive way.