Concerning the Islamic headscarf case and for a decision on a similar issue by the US Supreme Court, see:
https://www.supremecourt.gov/qp/14-00086qp.pdf  
or
https://www.bbc.com/news/world-us-canada-31626957 
or
https://en.wikipedia.org/wiki/Equal_Employment_Opportunity_Commission_v._Abercrombie_%26_Fitch_Stores

Anexos