by J. Fouchier and F. Billet. by F. Hercik and H. Jammet. by M. W. Porter and R. C. Spiller. by J.W. Weller and A. Youle. by R. G. Palmer and A. Platt. by A. C. Ainger and H. G. Wintle. by D.R. Strayer and D.H. Gillespie. by E. T. Whittaker and G. N. Watson. by P. E. Conner and E. E. Floyd. by R.E. Kaiser and E. Oelrich.