@PhDThesis{Straccia99a,                                                  
    Author = "Straccia, Umberto",                                                 
    Title = "Foundations of a Logic based approach to 
             Multimedia Document Retrieval",          
    School = "Department of Computer Science, University of Dortmund",             
    Year = "1999",
    Month = "June"                                                                
    }