1. Dean, F. B., Stasiak, A., Koller, T. & Cozzarelli, N. Duplex dna knots produced by escherichia coli topoisomerase 1. structure and requirements for formation. J. Biol. Chem. 260, 4975–83. http://www.jbc.org/content/260/8/4975.abstract (1985).
2. Stasiak, A., Katritch, V., Bednar, J., Michoud, D. & Dubochet, J. Electrophoretic mobility of dna knots. Nature 384, 122–122, https://doi.org/10.1038/384122a0 (1996).
3. Katritch, V. et al. Geometry and physics of knots. Nature 384, 142–145, https://doi.org/10.1038/384142a0 (1996).
4. Rolfsen, D. Knots and Links. Amer. Math. Soc. https://books.google.com/books?id=s4eGEecSgHYC (AMS Chelsea Pub., 1976).
5. Arteca, G. A. Scaling regimes of molecular size and self-entanglements in very compact proteins. Phys. Rev. E 51, 2600–2610, https://doi.org/10.1103/PhysRevE.51.2600 (1995).