source:[1] Post Holdings approves $500 million share buyback authorization (https://www.streetinsider.com/Stock+Buybacks/ ...)[2] Post Holdings Announces Sale of Pasta Business; New Share ... (https://finance.yahoo.com/news/post-holdings- ...)[3] Post Holdings Introduces $500 Million Share Buyback Plan (https://investorshangout.com/post-holdings-in ...)