Prospect Retrospective: the career of Ryan Howard - Minor League Ball
Ryan Howard, Baseball Wiki
Former All-Star Ryan Howard officially announces his retirement ~ Philadelphia Baseball Review - Phillies News, Rumors and Analysis
Former Philadelphia Phillies star Ryan Howard officially retires with 'Thank You, Philly' letter - 6abc Philadelphia
Ryan Howard – Society for American Baseball Research
Ryan Howard - Bio, News, Photos - Washington Times
Ryan Howard retires from baseball, Baseball
Philadelphia Phillies great Ryan Howard announces his retirement
Former Philadelphia Phillies star Ryan Howard officially retires with 'Thank You, Philly' letter - 6abc Philadelphia