1. B.Basili et C.Peskine, D�composition du fibr� normal des surfaces lisses de ?4 et structures doubles sur les solides de ?5. Preprint.
2. R.Braun, �ber das Normalenb�ndel von projektiven Variet�ten. Dissertation. Bayreuth 1989.
3. M.-C. Chang, Classification of Buchsbaum subvarieties of codimension 2 in projective space. J. Reine Angew. Math.401, 101?112 (1989).
4. G. Ellingsrud, L. Gruson, C. Peskine andS. A. Str�mme, On the normal bundle of curves on smooth projective surfaces. Invent. Math.80, 181?184 (1985).
5. H. Flenner, The infinitesimal M. Noether theorem for singularities. Compositio Math.59, 41?50 (1986).