edited by E.S. Vizi and K. Magyar. edited by H.C. Gooi and H. Chapel. edited by R.W. Frei and K. Zech. edited by H.D. Bui and Q.S. Nguyen. edited by R. Heim and G. Palm. edited by W. Oettli and K. Ritter. edited by P. L. Butzer and J. Korevaar. edited by R.W. Frei and J.F. Lawrence. edited by H.-W. Georgii and J. Pankrath. edited by B. Sz.-Nagy and L. Hatvani.