@article{JIS_2016__19_8_a3,
     author = {Haukkanen,  Pentti and Merikoski,  Jorma K. and Tossavainen,  Timo},
     title = {On arithmetic partial differential equations},
     journal = {Journal of integer sequences},
     year = {2016},
     volume = {19},
     number = {8},
     zbl = {1353.11007},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/JIS_2016__19_8_a3/}
}