@article{10_4064_sm198_3_4,
     author = {Sungeun Jung and Eungil Ko and Mee-Jung Lee},
     title = {On class {A} operators},
     journal = {Studia Mathematica},
     pages = {249--260},
     year = {2010},
     volume = {198},
     number = {3},
     doi = {10.4064/sm198-3-4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm198-3-4/}
}