___

• [1] Asil, V. and Bekta¸s, M. On a characterization of helix for curves of the Heisenberg group. Int. Journal of Pure and Applied Mathematics, V 15 No. 4 (2004), 491-495.
• [2] Balgetir, H., Bekta¸s, M. Ergu¨t, M., On a characterization of null helix. Bull. Ins. Math. Aca.Sin., 29, No. 1 (2001), 71-78.
• [3] Caddeo, R., Oniciuc, C. and Piu, P. Explicit formulas for non-geodesic biharmonic curves of the Heisenberg group. Rend. Sem. Mat. Univ. Politec. Torino, Vol 62 (3), (2004), 265-277.
• [4] Chen, B.-Y. and Ishikawa, S. Biharmonic surfaces in pseudo-Euclidean spaces. Mem. Fac. Sci. Kyushu Univ. Ser. A 45 (1991), 323–347.
• [5] Eells, J., Sampson, J.H. Harmonic mappings of Riemannian manifolds. Amer. J. Math. 86 (1964), 109-160.
• [6] Ekmekçi, N., Hacisalihog˘lu, H.H. On helices of a Lorentzian manifold. Commun. Fac. Sci., Univ. Ank. Series A1 (1996), 45-50.
• [7] Ekmekçi, N., I˙larslan, K. On characterization of general helices in Lorentzian space. HadronicJ. 23 (2000), no. 6, 677-682.
• [8] Ekmekci, N. On general helices and pseudo-Riemannian manifolds. Comm. Fac. Sci. Univ. Ankara. Series A1 V. 47. (1998), 45-49.
• [9] Ikawa, T. On curves and submanifolds in an indefinite Riemannian manifold. Tsukuba J. Math., 9 (1985), 353-371.
• [10] İlarslan, K. Characterizations of spacelike general helices in Lorentzian manifolds. KragujevacJ. Math. 25 (2003), 209-218.
• [11] Nakanishi, Y. On helices and pseudo-Riemannian submanifolds. Tsukaba J. Math. 12 (1988), 469-476.
• [12] Ogrenmis, A. O., Ergut, M. and Bektas, M. On the helices in the Galilean space G3. Iranian Journal of Science and Technology, Transaction A, Vol. 31 (2007).
• [13] Rahmani, S. Metriqus de Lorentz sur les groupes de Lie unimodulaires, de dimension trois. Journal of Geometry and Physics 9 (1992), 295-302.
• [14] Struik, D. J. Lectures on classical differential geometry. Dover, New-York, 1988.