=== ملاحظات ====== كتب ===* Sir Rudolf Bing, "5,000 Nights at the Opera: The Memoirs of Sir Rudolf Bing" ‏(Doubleday, 1972).
==References=====Notes======Books===* Sir Rudolf Bing, "5,000 Nights at the Opera: The Memoirs of Sir Rudolf Bing" (Doubleday, 1972).