@article{10_4064_sm186_3_1,
     author = {S. Petermichl and J. Wittwer},
     title = {Heating of the {Beurling} operator:
 {Sufficient} conditions for the two-weight case},
     journal = {Studia Mathematica},
     pages = {203--217},
     publisher = {mathdoc},
     volume = {186},
     number = {3},
     year = {2008},
     doi = {10.4064/sm186-3-1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm186-3-1/}
}