Everad Digby: De arte natandi libti duo. http://www.joh.cam.ac.uk/library/special_collections/early_books/pix/natandi.htm; Arnd Krüger & John McClelland (Hrsg.): Die Anfänge des modernen Sports in der Renaissance. London: Arena 1984; John McClelland: Body and Mind: Sport in Europe from the Roman Empire to the Renaissance (Sport in the Global Society). London: Routledge 2007