SI Vault on X: On this day in 1990, Don Mattingly signed a $19.7 million, five-year contract with the Yankees: / X
1987-08-11 MLB Inside Look - Don Mattingly interview
Matt Carpenter on mustache fame, Yankees chance, special salsa
The Yankees are bringing the mustache back in style - Pinstripe Alley
Yankees hit rock bottom as they go under .500 in August for first time in almost 30 years
The Tuesday Discussion: My Favorite Yankees First Baseman
The Yankees' appearance policy and why it should stay, Bronx Pinstripes
Is Don Mattingly the only New York Yankees player to not be booed by New York Yankee fans at Yankee Stadium? If so, why? - Quora
An Appreciation for Don Mattingly's Mustache in the 1980s - Men's Journal
Yankees: Matt Carpenter mustache loved by MLB fans
Baseballer - Nestor Cortes is rocking mustache cleats
Legendary mustache-haver Don Mattingly bans facial hair on Marlins
An Appreciation for Don Mattingly's Mustache in the 1980s - Men's Journal
Mustache craze grows in Yankees clubhouse – New York Daily News