an Entity references as follows:
This is a listing of the history of the World Record for the 50 backstroke swimming event. Swimming World Records are maintained by FINA, the international sports federation which oversees the sport. World Records are recognized only in meter-courses: long course (50m) and short course (25m). Like the other 50s of stroke (i.e. 50 breaststroke, 50 butterfly), World Record status/monitoring for this event first began in the 1990s.