@article{10_4064_sm195_3_5,
     author = {Leonid V. Kovalev and Jani Onninen},
     title = {Variation of quasiconformal mappings on lines},
     journal = {Studia Mathematica},
     pages = {257--274},
     publisher = {mathdoc},
     volume = {195},
     number = {3},
     year = {2009},
     doi = {10.4064/sm195-3-5},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm195-3-5/}
}