@article{JGG_2014_18_1_JGG_2014_18_1_a7,
     author = {J. Schadlbauer and H.-P. Schr�cker },
     title = {Orthogonality {Relations} for {Tetrahedra} in {Elliptic} and {Hyperbolic} {Space}},
     journal = {Journal for geometry and graphics},
     pages = {97--104},
     publisher = {mathdoc},
     volume = {18},
     number = {1},
     year = {2014},
     url = {http://geodesic.mathdoc.fr/item/JGG_2014_18_1_JGG_2014_18_1_a7/}
}