1. Differential Geometry;Auslander,1967
2. Trigonometry in Lorentzian geometry;Birman;Amer. Math. Monthly,1984
3. A.C. Çöken, Joachimsthal theorem for hypersurfaces in the semi-Euclidean spaces, Doctoral Dissertation, Osmangazi University Graduate School of Natural and Applied Science, Department of Mathematics, Eskişehir, 1995