"NFL Single-Season Receiving Yards Leaders". Pro-Football-Reference.com. Sports Reference. Retrieved October 19, 2016.(At the time of the merger, no NFL player had matched Hirsch's single-season record. However, two AFL players [ Charlie Hennigan in 1961 and 1964 and Lance Alworth in 1965] had exceeded Hirsch's mark, and those totals were merged into the NFL record book at the time of the merger.)