Algebraic Threefolds : Proceedings of the 2nd1981 Session of the Centro Internazionale Matematico Estivo (C.I.M.E.) Held at Varenna Italy June 15–23 1981 Bimeromorphic geometry of algebraic and analytic threefolds Classification of Fano threefolds according to Fano and Iskovskih Degeneration techniques in the study of threefolds Threefolds whose canonical bundles are not numerically effective Les singularites du diviseur  de la jacobienne intermediaire de l’hypersurface cubique dans IP4 The fundamental group of the Fano surface I The fundamental group of the Fano surface II On threefolds whose hyperplane sections are enriques surfaces Ample divisors on 3 folds Revetements cycliques Some questions on the canonical ring of threefolds of general type Deformations of irregular threefolds Plane forms and multiple point formulas.