Derived tubular algebras and APR-tilts Seminar on algebraic geometry at Bois Marie 1962-64. Group schemes (SGA 3). Vol. I: General properties of group schemes. Directed by M. Damazure and A. Grothendieck with the collaboration of M. Artin, J.-E. Bertin, P. Gabriel, M. Raynaud and J.-P. Serre 