@article{PORMA_1995__52_4_47459,
     author = {Abdel-All, N.H.},
     title = {Singular {Klein} manifolds.},
     journal = {Portugaliae mathematica},
     pages = {499--509},
     publisher = {mathdoc},
     volume = {52},
     number = {4},
     year = {1995},
     zbl = {0842.53009},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1995__52_4_47459/}
}