@article{KSS12,
	Author = {D. Kr{\'a}l' and J.-S. Sereni and L. Stacho},
	Journal = {SIAM J. Discrete Math.},
	Title = {Min-max relations for odd cycles in planar graphs},
  Volume = {26},
  Number = {3},
  Pages = {884--895},
  Year = {2012}}