 Compilation of Thermal Properties of Hydrogen in Its Various Isotopic and Ortho-Para Modifications by Harold W. Woolley and others

Journal of Research of the National Bureau of Standards 41, 379–475 (1948), RP1932. DOI: doi.org/10.6028/jres.041.037

Section III.2 and table 12 give ortho–para equilibrium composition and compare state sums with spectral and thermal evidence. The compilation distinguishes fixed-composition normal hydrogen from equilibrium spin isomers of hydrogen mixtures. It supplies institutional thermodynamic data and theory, rather than answers to a particular examination.