@article{10_4153_CJM_1993_059_2,
     author = {Stroethoff, Karel},
     title = {Essentially {Commuting} {Toeplitz} {Operators} {With} {Harmonic} {Symbols}},
     journal = {Canadian journal of mathematics},
     pages = {1080--1093},
     year = {1993},
     volume = {45},
     number = {5},
     doi = {10.4153/CJM-1993-059-2},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1993-059-2/}
}