1. Proc. Ind. Acad. Sci., 1938,8, 294.
2. See S. Bhagavantam and T. Venkatarayudu,Theory of Groups and Its Application to Physical Problems (1951), for further details.
3. Göttingen Nachricten, 1930, 133.
4. Zeit. f. Phys., 1930,81, 209.
5. Zeit. f. Phys., 1933,82, 48.