Elfi Kraka Dieter Cremer The para-didehydropyridine, para-didehydropyridinium, and related biradicals - a contribution to the chemistry of enediyne antitumor drugs. 216-229 2001 22 Journal of Computational Chemistry 2 http://dx.doi.org/10.1002/1096-987X(20010130)22:2<216::AID-JCC9>3.0.CO;2-X db/journals/jcc/jcc22.html#KrakaC01