@article{JAC_2012__36_3_a1,
     author = {Danilov, Vladimir I. and Karzanov, Alexander V. and Koshevoy, Gleb A.},
     title = {Planar flows and quadratic relations over semirings},
     journal = {Journal of Algebraic Combinatorics},
     pages = {441--474},
     publisher = {mathdoc},
     volume = {36},
     number = {3},
     year = {2012},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/JAC_2012__36_3_a1/}
}