Horse race on post stamp

Keywords:

collection, stamp, picture, communications, postage, mail, post, postmark, label, zigzag, canceled, mark, philately, symbol, vintage, Bulgaria, mammal, animal, horse, yellow, brown, rider, horse-race, race, ride, competition, sport, compete, price, dressage, equestrian, horseback, horseracing, elegance, triathlon, jump, show, jumping, barrier, hurdle,