Unified quantum mechanical picture for confined spinons in dimerized and frustrated spin S=1/2 chains G. S. Uhrig, F. Schönfeld, M. Laukamp and E. Dagotto Eur. Phys. J. B, 7 1 (1999) 67-77 Published online: 15 January 1999 DOI: 10.1007/s100510050589