@article{JEMS_2012_14_3_a4,
     author = {Kilian Raschel},
     title = {Counting walks in a quadrant: a unified approach via boundary value problems},
     journal = {Journal of the European Mathematical Society},
     pages = {749--777},
     publisher = {mathdoc},
     volume = {14},
     number = {3},
     year = {2012},
     doi = {10.4171/jems/317},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/jems/317/}
}