http://www.sec.gov/Archives/edgar/data/1114446/000091412117001085/ub37420115-424b2.htm
http://www.sec.gov/Archives/edgar/data/1000275/000114036117032529/form424b2.htm
http://www.sec.gov/Archives/edgar/data/761648/000119312517261053/d430623d424b5.htm
http://www.sec.gov/Archives/edgar/data/1390777/000119312517261110/d395480d424b2.htm
http://www.sec.gov/Archives/edgar/data/1423689/000142368917000040/prospectussupplement.htm
http://www.sec.gov/Archives/edgar/data/1711142/000153949717001423/n987_424b.htm
http://www.sec.gov/Archives/edgar/data/1692819/000169281917000017/vistra-081717x424b3.htm