Stability and hyperfine structure of the four- and five-body muon-atomic clusters a+b+μ−e− and a+b+μ−e−e−A.M. Frolov and D.M. WardlawEur. Phys. J. D, 66 5 (2012) 132DOI: https://doi.org/10.1140/epjd/e2012-30076-6