Z. Balogh, P. Koskela, S. Rogovin:
Absolute continuity continuity of quasiconformal mappings on curves
GAFA (Accepted Paper) 2007

P. Koskela, M. Miranda Jr, N. Shammugalingam:
Geometric properties of planar BV-extension domains
in "Around the research of Vladimir Maz'ya. {I}" Vol. 11, 2010

P. Koskela, M. Miranda Jr, N. Shanmugalingam:
Geometric properties of planar BV-extension domains
International Mathematical Series (N.Y.) Vol. 11, N. 1, p. 255-272, 2010

K. Fässler, P. Koskela, E. Le Donne:
Nonexistence of quasiconformal maps between certain metric measure
  spaces
(preprint) 2013