structure fine
1985 / The Fine Structure of Hydrogen and the Gross Structure of the Physics Community, 1916-26 / Helge Kragh / Historical Studies in the Physical Sciences 15 (1985) p. 67 [doi]
2014 / The fine structure of Hydrogen and Hydrogen-like lines / A. Sommerfeld / European Journal of Physics H 39 (2014) p. 179 [doi]