@article{DMGAA_2010_30_2_a5,
     author = {Shtrakov, Slavcho and Koppitz, J\"org},
     title = {On finite functions with non-trivial arity gap},
     journal = {Discussiones Mathematicae. General Algebra and Applications},
     pages = {217--245},
     publisher = {mathdoc},
     volume = {30},
     number = {2},
     year = {2010},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DMGAA_2010_30_2_a5/}
}