Sum rules and dualities for generalized parton distributions: is there a holographic principle? K. Kumerički, D. Müller and K. Passek-Kumerički Eur. Phys. J. C, 58 2 (2008) 193-215 Published online: 09 October 2008 DOI: 10.1140/epjc/s10052-008-0741-0