Jerry Koosman's number retirement, 08/28/2021
Jerry Koosman to Have Number Retired on August 28, 2021 - Metsmerized Online
Mets to Retire Jerry Koosman's Jersey - The New York Times
Jerry Koosman – Society for American Baseball Research
Jerry Koosman's No. 36 retired by Mets
Mets announce Jerry Koosman number retirement date –
List of Major League Baseball retired numbers - Wikipedia
April 23, 1969: Jerry Koosman gets his first win in Mets' miracle season – Society for American Baseball Research
Mike Piazza pays tribute to 'baseball icon' Tom Seaver
Mets to Retire Jerry Koosman's Jersey - The New York Times