@article{MZ_1968__105_170977,
     author = {David A. Drake},
     title = {Projective {Extensions} of {Uniform} {Affine} {Hjelmslev} {Planes.}},
     journal = {Mathematische Zeitschrift},
     pages = {196--207},
     publisher = {mathdoc},
     volume = {105},
     year = {1968},
     zbl = {0155.29801},
     url = {http://geodesic.mathdoc.fr/item/MZ_1968__105_170977/}
}