by R. Belcher and A. L. Godbert. [by] R. Belcher [and] A. L. Godbert. by J. H. Cairns and P. T. Gilbert. by J. Fouchier and F. Billet. by R. Courant and D. Hilbert. by J.W. Weller and A. Youle. Tony J. Pitcher and Paul J.B. Hart. H. Halberstam and H. E. Richert.