A group of background papers:
M V Sussman, "Reflections on a rubber band and supercoiled DNA" (typescript, 19 June, 1981);
Stettler, Weber, Koller and Weissmann, "Preparation and characterization of form V DNA, the duplex DNA resulting from association of complementary, circular single-stranded DNA," Journal of Molecular Biology, 131 (1979), 21-40 (photocopy);
Patel, Canuel and Pohl, "'Alternating B-DNA' conformation for the oligo (dG-dC) duplex in high-salt solution," Proc. Natl. Acad. Sci., 76: 6 (1979), 2508-11 (photocopy);
Wang, "Helical repeat of DNA in solution," Proc. Natl. Acad. Sci., 76: 1 (1979), 200-3 (photocopy);
Levitt, "How many base-pairs per turn does DNA have in solution and in chromatin? Some theoretical calculations," Proc. Natl. Acad. Sci., 75: 2 (1978), 640-44 (reprinted paper);
Pohl and Roberts, "Topological considerations in the theory of replication of DNA" (typescript, n.d.);
Sasisekharan and Pattabiraman, "Structure of DNA predicted from stereochemistry of nucleoside derivatives," Nature, 275 (1978), 159-62 (photocopy);
Bauer, "Structure and reactions of closed duplex DNA," Ann. Rev. Biophys. & Bioeng (1978, pre-publication typescript);
Banchoff and White, "The behaviour of the total twist and self-linking number of a closed space curve under inversions," Mathematica Scandinavica, 36 (1975), 254-62 (photocopy);
Pulleyblank and Morgan, "The sense of naturally-occurring superhelices and the unwinding angle of intercalated ethidium," Journal of Molecular Biology, 91 (1975), 1-13 (photocopy);
Liu and Wang, "On the degree of unwinding of the DNA helix by ethidium," Biochimica et Biophysica Acta, 395 (1975), 405-12 (photocopy);
Pohl, Jovin, Baehr and Holbrook, "Ethidium bromide as a cooperative effector of a DNA structure," Proc. Natl. Acad. Sci., 69: 12 (December, 1972), 3805-9 (photocopy);
Fuller, "The writhing number of a space curve," Proc. Natl. Acad. Sci., 68: 4 (April, 1971), 815-9 (photocopy);
and Pohl, "The self-linking number of a closed space curve," Journal of Mathematics and Mechanics, 17: 10 (1968), 975-85 (photocopy).