Effective interactions and the hydrogen atom
The published version is located at http://ajp.aapt.org/resource/1/ajpias/v72/i3/p333_s1
The technique of effective interactions, which has become commonplace in contemporary particle/nuclear physics, is used to analyze the structure of hydrogen atom energy levels.
BR Holstein. "Effective interactions and the hydrogen atom" American Journal of Physics 72.3 (2004): 333-334.
Available at: http://works.bepress.com/barry_holstein/96