1. BorelArc. Sci. Phy. Nat., 1903,16, 24; 157.
2. ChandrasekharProc. Ind. Acad. Sci., 1951,34 A, 275.
3. CottonComp. Rend., 1931,192, 1166.
4. DischAnn. der. Physik., 1903,12, 1153.
5. HellerWeissberger’s Physical Methods in Organic Chemistry, Part II, 1949.