[1] Refer to B.R.  Brooks, R.E.  Bruccoleri, B.D.Olafson, D.J.  States, S.  Swaminathan, and M.  Karplus.  CHARMM: A program for macromolecular energy, minimization, and dynamics calculations.  J.  Comput.  Chem.  4 187-217 (1983).

[2] TUCOWS is an acronym for The Ultimate Collection of Windows Software.  See www.tucows.com.

[3] This is not intended as a product endorsement.