1. G. C. Pimentel and A. L. McClellan,The Hydrogen Bond(W. H. Freeman and Company, San Francisco, California, 1960).
2. The authors have been informed in a private communication that some of these lines have also been observed by R. Keller and W. D. Gwinn, University of California.
3. K. J. Gallagher,Hydrogen Bonding, Ljubljana Conference, edited by D. Hadgi (Pergamon Press, New York, 1959), p. 48.
4. N. Sheppard,Hydrogen Bonding, Ljubljana Conference, edited by D. Hadgi (Pergamon Press, New York, 1959), p. 92.