The Undertaker, For Extreme Wiki
Random Network Reviews: NWA Clash of the Champions VIII: Fall Brawl
Throwback Thursday: NWA/WCW Clash of the Champions X: Texas Shootout, As Seen on WWE Network
The Undertaker – Online World of Wrestling
Clash of the Champions X: Texas Shootout (TV Special 1990) - IMDb
Before The Undertaker: The best of Mean Mark Callous on WWE Network
Undertaker Wins First Championship at 1991 Survivor Series – Rolling Stone
Styles Clash: Clash of the Champions XI: Coastal Crush
33 Forgotten Moments In The Undertaker's WWE Career – Page 5
Styles Clash: Clash of the Champions XI: Coastal Crush