Tobias Scheunchen (eds.), "al-Falaj - الفلج " in The Beth Qaṭraye Gazetteer last modified January 10, 2020, https://bqgazetteer.bethmardutho.org/place/5027
  
    
      
        
          al-Falaj
          الفلج
          
          A citadel situated a six days-journey from Hajar and an nine days-journey from Mecca.
          https://bqgazetteer.bethmardutho.org/place/5027
          http://syriaca.org/place/5027
          
            Kitāb al-Masālik wa al-mamālikAbū ʿUbayd al-Bakrī
            1377