Peyton Manning to retire after 18 NFL seasons
Peyton Manning to Retire After 18 NFL Seasons - Bloomberg
Peyton Manning's No. 18 Retired By Colts; Enters Ring Of Honor
Peyton Manning to announce retirement Monday - ESPN
Peyton Manning calling it a career after 18 NFL seasons
AP source: Peyton Manning to retire after 18 NFL seasons
Peyton Manning retirement: Broncos should re-retire the No. 18
Peyton Manning to retire, Broncos say
Peyton Manning: 'I'll always be a Colt'