Saha, Megh Nad (1920). "LIII.Ionization in the solar chromosphere". Philosophical Magazine Series 6. 40 (238): 472. doi:10.1080/14786441008636148.
Saha, M. N. (1921). "On a Physical Theory of Stellar Spectra". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences. 99 (697): 135. Bibcode:1921RSPSA..99..135S. doi:10.1098/rspa.1921.0029.
Saha, M. N. (1921). "On a Physical Theory of Stellar Spectra". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences. 99 (697): 135. Bibcode:1921RSPSA..99..135S. doi:10.1098/rspa.1921.0029.