@article{MZ_1968__108_171089,
     author = {Ferdinand D. Veldkamp},
     title = {Collineation {Groups} in {Hjelmslev-Moufang} {Planes.}},
     journal = {Mathematische Zeitschrift},
     pages = {37--52},
     publisher = {mathdoc},
     volume = {108},
     year = {1968},
     zbl = {0165.54601},
     url = {http://geodesic.mathdoc.fr/item/MZ_1968__108_171089/}
}