1. aMcCrone, W. C.Polymorphism in Physics and Chemistry of the Organic Solid State;Fox, D., Labes, M. M., and Weissberger, A., Eds.Interscience:New York, 1965; Vol.II, p725.
2. bBernstein, J.;Oxford University Press:New York, 2002.
3. aBurger, A.Topics in Pharmaceutical Sciences;Breimer, D. D. and Speiser, P., Eds.Elsevier:Amsterdam, 1983; p347.
4. Analysis of organic polymorphs. A review
5. Polymorphic Perversity: Crystal Structures with Many Symmetry-Independent Molecules in the Unit Cell