1. U. Abresch: Constant mean curvature tori in terms of elliptic functions, preprint MPI/SFB 85-50 (Bonn), to appear in Crelle Journal.
2. S.N. Chow, J.K. Hale: Methods of bifurcation theory, Springer, New York Berlin Heidelberg 1982.
3. G. Darboux: Leçons sur la théorie générale des surfaces et les applications géométriques du calcul infinitésimal, 2nd ed., Gauthier-Villars, Paris 1915.
4. L.P. Eisenhart: An introduction to differential geometry, PUP 1947.
5. N.M. Ercolani, M.G. Forest: The Geometry of real sine-Gordon wavetrains, Comm. Math. Phys. 99 (1985), 1–49.