Researcher, Consejo Superior de Investigaciones Científicas (C.S.I.C. – Spanish Council for Scientific Research), Spain
- 2016 - G. Bombieri, University of Torino (Italy)
- 2008 - G. Szabó, University of Pécs (Hungary)
- 2008 - C. Bettega, University of Padova (Italy)
- 2007 - E. Caferri, University “La Sapienza” (Italy)
- 2007 - E. Zago, University “La Tuscia” (Italy)
- 2006 - N. Margnelli, University “La Tuscia” (Italy)