1. [A-K] Altman, A., Kleiman, S.: Introduction to Grothendieck duality theorem. In: Lecture Notes in Mathematics, Vol. 146. Berlin, Heidelberg, New York: Springer, 1970
2. [A-M] Alibert, D., Maltsiniotis, G.: Groupe fondamental du complémentaire d'une courbe à points doubles ordinaires. Bull. Soc. Math. France102, 335?351 (1974)
3. [D-M] Deligne, P., Mumford, D.: The irreducibility of the space of curves of given genus. Publ. Math. I.H.E.S.36, 75?100 (1969)
4. [FUL1] Fulton, W.: Algebraic curves. New York, Amsterdam: Benjamin 1969
5. [FUL2] Fulton, W.: On the irreducibility of the moduli space of curves. Appendice à l'article de J. Harris et D. Mumford. Invent. Math.67, 87?88 (1982)