by D. F. Spooner and W. H. Grinsted. by A. C. Ainger and H. G. Wintle. by P. E. Conner and E. E. Floyd. M. c. Sneed and R. C. Brasted. by C. Zwikker and C. W. Kosten. by C.J. Cowper and A.J. DeRose. by J. C. Jaeger and A. M. Starfield. by J. Kroonen and D. Vander. by D.J. Littler and J.F. Raffle. by E. T. Whittaker and G. N. Watson.