A one-page typed letter in German signed by Albert Einstein referring to Sir Isaac Newton; an autograph letter signed twice by General George A. Custer with Battle of Little Big Horn associations; and a crisp sepia-toned photograph of then-President Theodore Roosevelt signed and dedicated to Pope Pius X are just a few of the historically significant items bidders will vie for in University Archives’ online-only Rare Signed Autographs, Manuscripts, Books & Memorabilia auction on Wednesday, Sept. 18.