Aldo Antognini: Muonic atoms and the nuclear structure. In: arXiv:physics. 10. August 2016, arxiv:1512.01765 (ICOLS 2015, Singapore).
doi.org
Willis E. Lamb, Robert C. Retherford: Fine Structure of the Hydrogen Atom by a Microwave Method. In: Physical Review. Band72, Nr.3, 1947, S.241–243, doi:10.1103/PhysRev.72.241.