P.L. Raston*, S.C. Kettwich, and D.T. Anderson, Infrared studies of ortho-para conversion at Cl-atom and H-atom impurity centers in cryogenic solid hydrogen, Low Temp. Phys. 36, (2010) [Fiz. Nizk. Temp. 36, 495-503, (2010)] DOI: https://doi.org/10.1063/1.3432246.