Petek H., D.J. Nesbitt, D.C. Darwin, P.R. Ogilby, C.B. Moore, and D.A. Ramsay, The Journal Of Chemical Physics 91, 6566 (1989).
Petek H., D.J. Nesbitt, C.B. Moore, F.W. Birss, and D.A. Ramsay, The Journal Of Chemical Physics 86, 1189 (1987).