References for William 4th Duke, 3rd Earl, 3rd Earl Douglas * of Queensberry * of March * of Ruglen

---

Sir B.Burke: The Dormant and Extinct Peerage. London, 1866
Sir B.Burke: A Genealogical History of the Peerages and Knightages of the British Empire. London, 1953
Sir B.Burke: Burke's Peerage and Baronetage. London, 1999