1. E. Abe, Hopf Algebras, Cambridge Univ. Press, Cambridge, 1977.
2. Finiteness conditions, co-Frobenius Hopf algebras, and quantum groups;Beattie;J. Algebra,1998
3. C. Calinescu, Integrals for Hopf algebras, Dissertation, University of Bucharest, 1998.
4. On projective modules for algebraic groups;Donkin;J. London Math. Soc.,1996
5. Semiperfect coalgebras;Lin;J. Algebra,1977