Helix to helix packing in proteins.

MLA

Chothia, C., et al. “Helix to Helix Packing in Proteins.” Journal of Molecular Biology, vol. 145, no. 1, Jan. 1981, pp. 215–50. EBSCOhost, https://doi.org/10.1016/0022-2836(81)90341-7.

APA

Chothia, C., Levitt, M., & Richardson, D. (1981). Helix to helix packing in proteins. Journal of Molecular Biology, 145(1), 215–250. https://doi.org/10.1016/0022-2836(81)90341-7

Chicago

Chothia, C, M Levitt, and D Richardson. 1981. “Helix to Helix Packing in Proteins.” Journal of Molecular Biology 145 (1): 215–50. doi:10.1016/0022-2836(81)90341-7.