by G.E. Beaumont and E.C. Dodds. by G.D. Elliot and J.A. Bond. by H.J. Frost and M.F. Ashby. by N.F. Mott and E.A. Davis by W.B. Gillett and J.E. Moon. by B. R. T. Frost and M. B. Waldron. by D.T.E. Hunt and A.L. Wilson. by I. I. Berenblut and Anne B. Downes. by J. H. Simpson and R. S. Richards. by N. F. Mott and E. A. Davis.