found: Wikipedia, 7 April 2011(the Consolidated B-24 Liberator was an American heavy bomber, designed by Consolidated Aircraft Company of San Diego, California; the B-24 ended World War II as the most produced American military aircraft at over 18,000 units; the B-24 was used by several Allied air forces and navies, and by every branch of the American armed forces during the war.)
found: Carey, Alan C. U.S. Navy PB4Y-1 (B-24) Liberator squadrons in Great Britain during World War II, 2003:title (PB4Y-1, type of B-24)
found: Phonecall to the National Naval Aviation Museum Library staff in Pensacola, Florida, June 7, 2019:(PB4Y-1 was B-24; U.S. Navy gave it a Navy specific designator)
