by D. R. Beaman and J. A. Isasi. by F. H. Newman and V. H. L. Searle. by W. G. McLean and E. W. Nelson. by M. A. Grossmann and E. C. Bain. by R. Hosemann and S. N. Bagchi. by J. E. Gowan and T. S. Wheeler. by D.L. Klingman and W.C. Shaw. by A. D. McQuillan and M. K. McQuillan. by Stefan Bergman and M. Schiffer.