@article{10_37236_1438,
     author = {Anna Galluccio and Martin Loebl},
     title = {On the theory of {Pfaffian} orientations. {I:} {Perfect} matchings and permanents},
     journal = {The electronic journal of combinatorics},
     year = {1999},
     volume = {6},
     doi = {10.37236/1438},
     zbl = {0909.05005},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/1438/}
}