Proposals The CREMA Proposal on laser spectroscopy in muonic helium. Sidebar CREMA collaboration links Muonic hydrogen webpage, LKB Paris Muonic hydrogen webpage, MPQ Munich Hydrogen spectroscopy, MPQ Munich Precision physics at low energy, ETH Zurich Codata Values Hydrogen Energy Levels (NIST) Proton Radius value (NIST) Fundamental Physical Constants (NIST)