@article{JGG_2014_18_2_JGG_2014_18_2_a3,
     author = {D. Klawitter },
     title = {Null {Polarities} as {Generators} of the {Projective} {Group}},
     journal = {Journal for geometry and graphics},
     pages = {183--197},
     publisher = {mathdoc},
     volume = {18},
     number = {2},
     year = {2014},
     url = {http://geodesic.mathdoc.fr/item/JGG_2014_18_2_JGG_2014_18_2_a3/}
}