Jim Northrup Baseball Cards
15 Cent Cards One at a Time – Collecting one story and card at a time
Mayo Smith – Society for American Baseball Research
Jim Northrup Detroit Tigers Outfield Collectible Baseball
1966 Topps Baseball Cards Checklist, Set Info, Key Cards, More
Jim Northrup Autographed 1973 O-Pee-Chee Card #168 Detroit Tigers SKU #169214 - Mill Creek Sports
Topps 1971: February 2015
Rich's Reminiscences
Jim Northrup – Society for American Baseball Research
Jim Northrup Baseball Cards
CardCorner: 1973 Topps Bill Freehan
Kaline Baseball