Christian Louboutin's Red Shoe Soles are a valid Trademark.
The Worldwide Trademark Battle over the Iconic Red Bottom Shoe - Chicago-Kent
Will Christian Louboutin be a Fashion Victim in Trademark Infringement Case?
Louboutin Red-Sole & Surrounding Contrast: An Implied Trademark Limitation
Louboutin Lands Win in Chinese Case Over Red Sole Trademark
Christian Louboutin denied attempt to register red sole shoe as a trademark in Switzerland. — Fashion, Law & Business
The Fight for Red: Fashion Statement or Protected Trademark?
Louboutin v. YSL Red Sole Shoe Trademark Infringement
How Tiffany blue and Louboutin shoes are revealing trademark law's true colours - Legal Cheek
Position trademark and shape trademark: the Louboutin case - Canella Camaiora
Louboutin Wins EU Legal Battle for Trademark on Red Soles
Luxury Footwear China Trademark Case Victory