1990 Pro Set #351 Howie Long Values - MAVIN
One 1992 Pro Line football card's story includes three Super Bowl
Howie Long Football Trading Card Database
Howie Long Football Trading Card Database
1990 Pro Set Football Card Set - VCP Price Guide
1990 Pro Set Football Card #351 Howie Long PB
NCAuctions.com Auction Catalog - 2021 November Collectors Estate
PSA Magazine: 2022 August #008 by PSA Magazine - Issuu