“…Mixter, Barr, White and others have 'analysed results achieved at the Massachusetts General Hospital. Other authors include Dandy (1941), Bradford & Spurling (1947), Aitken & Bradford (1947, Lenhard (1947), Falconer et al (1948, Echols (1949), ), Burns & Young (1951, O'Connel (1951), Armstrong (1951), Pouyanne (1951), Ross & Jelsma (1952), Grantham & Spurling (1953, Raaf (1959), Reynolds et al (1959), Semmes (1964.…”