Norman Crider held an exhibition on which creator of the rule "The Dying Swan".
Norman Crider:  He also owned a gallery-bookshop on Madison Avenue where in 1977 he held an acclaimed exhibition on prima ballerina Anna Pavlova. Anna Pavlova:  Pavlova is most recognized for the creation of the role "The Dying Swan" and, with her own company, became the first ballerina to tour ballet around the world.
Anna Pavlova