@article{IM_1975__30_142350,
     author = {P. van Moerbeke and H.P. McKean},
     title = {The {Spectrum} of {Hill's} {Equation.}},
     journal = {Inventiones mathematicae},
     pages = {217--274},
     publisher = {mathdoc},
     volume = {30},
     year = {1975},
     zbl = {0319.34024},
     url = {http://geodesic.mathdoc.fr/item/IM_1975__30_142350/}
}