1. REQUIMTE-CQFB and Department of Conservation and Restoration, Faculdade de Ciências e Tecnologia; Universidade Nova de Lisboa; Campus da Caparica 2829-516 Caparica Portugal
2. Department of Scientific Research; The Metropolitan Museum of Art; 1000 Fifth Avenue New York NY 10028 USA
3. Department of Conservation Science; Art Institute of Chicago; 111 South Michigan Avenue Chicago IL 60603 USA