1. For a review of the basic formalism seeV. Alessandrini, D. Amati, M. Le Bellac andD. I. Olive:Phys. Rep.,1 C, No. 6 (1971).
2. A. Neveu andJ. H. Schwarz:Nucl. Phys.,31 B, 86 (1972);A. Neveu, J. H. Schwarz andC. B. Thorn:Phys. Lett.,35 B, 529 (1971).
3. P. Ramond:Phys. Rev. D,3, 2415 (1971).
4. A. Neveu andJ. H. Schwarz:Phys. Rev. D,4, 1109 (1971).
5. C. B. Thorn:Phys. Rev. D,4, 1112 (1971).