@article{CM_1989__71_3_285_0,
     author = {Hanssens, G. and Van Maldeghem, H.},
     title = {A universal construction for projective {Hjelmslev} planes of level $n$},
     journal = {Compositio Mathematica},
     pages = {285--294},
     publisher = {Kluwer Academic Publishers},
     volume = {71},
     number = {3},
     year = {1989},
     mrnumber = {1022046},
     zbl = {0709.51010},
     language = {en},
     url = {http://www.numdam.org/item/CM_1989__71_3_285_0/}
}