Rangers, Celtic and the Perils of a Zero-Sum Game - The New York Times
Celtic go solo with Magners - Sport for Business
Kit Crimes ⚽️ on Twitter: "The subject of rivals with the same shirt sponsors was raised by @RyanClayton4, so here's four times Celtic and Rangers had the same company on their shirts.
Celtic and Rangers on alert after Premier League clubs ban gambling shirt sponsors - Football Scotland
Celtic to wear special edition charity shirt for Dundee clash as club look to spread Christmas cheer - Football Scotland
Kit Crimes ⚽️ on Twitter: "@RyanClayton4 @TheKitmanUK @The_Kitsman Celtic and Rangers have had the same shirt sponsor more than once. https://t.co/CPhYQ1PkeP" / Twitter
SCOTTISH PREMIERSHIP FIXTURES: Celtic and Rangers will meet in first Old Firm on September 3 | Daily Mail Online
Odsonne Édouard seals Old Firm win for 10-man Celtic against Rangers | Scottish Premiership | The Guardian
Rangers and Celtic facing 'betting logo ban' in potential multi million pound shirt sponsorship blow - Daily Record