The hyperfine structure of the energy levels of the hydrogen atom refers to the shifts in the evergy levels due to the magnetic moments of the nucleus and of the electron. This is an effect of non-relativistic QM, if I understand correctly.
On the other hand, the Lamb shift in the energy levels is due to completely different reasons: it has nothing to do with the spin of nucleus, and can be explained only by the relativistic theory, i.e. QED.
How to compare these two effects? Which one is stronger? Is there any literature about this?
I do know references to literature about the Lamb shift. It would be helpful to have a reference to a detailed discussion of the hyperfine structure, and to a comparison with the lamb shift.