A Visual Object-Oriented Query Language for Geographic Information Systems - Fabrizio Di Loreto; Fernando Ferri; Fernanda Massari; Maurizio Rafanelli (DEXA, 1995)

A pictorial query language for geographical databases. - Fabrizio Di Loreto; Fernando Ferri; Fernanda Massari; Maurizio Rafanelli (AVI, 1996)

A Pictorial Query Language for Geographic Features in an Object-Oriented Environment. - Fernando Ferri; Fernanda Massari; Maurizio Rafanelli (J. Vis. Lang. Comput., 1999)