From The Guerrilla Girls description of Art Museum Activity Book:

"Go behind the pretty pictures. Wallow in the dirt that museums hope you haven’t noticed. Take our fun tests; do the math. Get ideas for how you can bother, and maybe change, your favorite museum, just like we’ve been doing."

The Guerrilla Girls define themselves as a feminist activist group “using facts, humor and outrageous visuals to expose gender and ethnic bias as well as corruption in politics, art, film, and pop culture.” The group of anonymous activists well known for wearing a gorilla mask in public appearances was formed in 1985 in the aftermath of protests in response to an exhibition at the Museum of Modern Art in New York in 1984. Titled “An International Survey of Recent Paintings and Sculpture,” curated by Kynaston McShine, it included 165 artists, only 13 of them women.

 Learn more about The Guerrilla Girls here (link)