1. Appel, K.I., Haken, W.: Every Planar Map is Four Colorable, vol. 98. American Mathematical Soc. (1989)
2. Barras, B., et al.: The coq proof assistant reference manual. INRIA, version 6(11) (1999)
3. Lecture Notes in Computer Science;G Bauer,2001
4. Bertot, Y., Castran, P.: Interactive Theorem Proving and Program Development: Coq’Art The Calculus of Inductive Constructions, 1st (edn.) Springer, Incorporated (2010)
5. Lecture Notes in Computer Science;A Bove,2009