You may also wish to search for items by Critchfield, F. and Critchfield.
Only one matching reference was found.
Critchfield, F.E.; Gibson, J.A.; Hall, J.L., Dielectric constant and refractive index from 20 to 35 c and density at 25 c for the system tetrahydrofuran + water, J. Am. Chem. Soc., 1953, 75, 6044. [all data]