1. AshtekarA., New Hamiltonian formulation of general relativity, Phys. Rev. D36, 1587?1602 (1987).
2. Baez, J., Quantum gravity and the algebra of tangles, UC Riverside preprint, 1992.
3. Bar-Natan, D., Weights of Feynman diagrams and the Vassiliev knot invariants, Princeton University preprint, 1991; Bar-Natan, D., Isotopy invariance for knots in perturbative Chern-Simons theory, Harvard University preprint, 1992.
4. BirmanJ., Braids, Links, and Mapping Class Groups, Princeton University Press, Princeton, 1974.
5. Birman, J. and Lin, X.-S., Knot polynomials and Vassiliev's invariants, Columbia University preprint, 1991.