Walter H. Breen

Walter H. Breen Jr. (September 5, 1928 – April 27, 1993) was an American numismatist, writer, LGBT rights activist and convicted child sex offender, and the husband of author Marion Zimmer Bradley. He is known among coin collectors for writing Walter Breen's Complete Encyclopedia of U.S. and Colonial Coins. "Breen numbers", from his encyclopedia, are widely used to attribute varieties of coins. He is also known for activity in the science fiction fan community and for his writings in defense of pederasty.