1. M.B. Green, J.H. Schwarz, E. Witten, Superstring Theory, Cambridge University Press, Cambridge, 1987.
2. D. Lüst, S. Theisen, Lectures on String Theory, Lecture Notes in Physics, Vol. 346, Springer, Berlin, 1989, 346 pp.
3. J. Polchinski, String Theory, Cambridge University Press, Cambridge, 1998.
4. Unified approach to strings and vortices with soliton solutions
5. A new geometric approach to the relativistic string