1. Weak Hopf algebras, I. Integral theory and C∗-structure;Böhm;J. Algebra,1999
2. S. Burciu, Normal Hopf subalgebras of a semisimple Hopf algebra, Proc. Amer. Math. Soc., in press
3. S. Burciu, Coset decomposition for semisimple Hopf algebras, Comm. Algebra, in press
4. Galois theory for weak Hopf algebras;Caenepeel;Rev. Roumaine Math. Pures Appl.,2007