1. Descent relations among bosonic D-branes;Sen;Int. J. Mod. Phys. A,1999
2. Boundary deformation theory and moduli spaces of D-branes;Recknagel;Nucl. Phys. B,1999
3. Exact solution of a boundary conformal field theory;Callan;Nucl. Phys. B,1994
4. Free fermion representation of a boundary conformal field theory;Polchinski;Phys. Rev. D,1994
5. For a recent review of the construction of D-branes through tachyon condensation (and especially the connection to K-theory) see: K. Olsen, R. Szabo, Constructing D-branes from K-theory, hep-th/9907140, Adv, Theor. Math. Phys., in press