1. Adobe Inc.: Adobe acrobat professional. http://www.adobe.com/products/acrobatpro/
2. Agosti, M., Benfante, L., Orio, N.: Ipsa: A digital archive of herbals to support scientific research. In: Proceedings of the International Conference on Asian Digital Libraries (ICADL), pp. 253–264 (2003)
3. Agosti, M., Albrechtsen, H., Ferro, N., Frommholz, I., Hansen, P., Orio, N., Panizzi, E., Pejtersen, A.M., Thiel, U.: DiLAS: a digital library annotation service. In: Proceedings of Annotation for Collaboration—A Workshop on Annotation Models, Tools and Practices (2005)
4. Agosti M., Ferro N.: Annotations: Enriching a digital library. In: Koch, T., Sølvberg, I.(eds) ECDL, Lecture Notes in Computer Science, vol. 2769, pp. 88–100. Springer, Berlin (2003)
5. Agosti M., Ferro N.: Annotations as context for searching documents. In: Crestani, F., Ruthven, I.(eds) CoLIS, Lecture Notes in Computer Science, vol. 3507, pp. 155–170. Springer, Berlin (2005)