Operation Bullpen: Be aware of these authenticators and autograph

Book Operation Bullpen Inside Story Biggest Forgery Scam Nelson

Operation Bullpen and the Marino Family Forgery Ring: Did anything

The Biggest Players in Sports Memorabilia Counterfeit

Operation Bullpen: Be aware of these authenticators and autograph

Baseball's Army of Authenticators - WSJ

Bats, Balls, Champagne Bottles, Even Urinals: How The MLB Authenticates Its Memorabilia

Operation Bullpen Bullpen & More, by Kevin Nelson

Top 10 FAKED Sports Autographs - Don't Get BURNED! Watch Before Your N

Babe Ruth Autographs, The Holy Grail – Brigandi Coins & Collectibles