I think I first learned of Sister Corita through Todd St. John back when I worked in his studio. He had one of her books, and the coolest print I've ever seen. I taped lots of her work to my walls when I lived in the teeniest apartment in the East Village. As I'm designing more and more of my own work, outside of the editorial world, I look to her even more for typogrpahy & composition inspiration.
All images found on a good ole google image search