National Conference "GIS: Geographic Information Systems : Challenge for the 1990's" Ottawa, Canada, Canada. Energy, Mines and Resources Canada, Canadian Association of Geographers, & Canadian Institute of Surveying and Mapping. (1989). GIS: Geographic information systems: Challenge for the 1990s = SIG: Systèmes d'information géographique : défi des années 90 : proceedings, National Conference, Candian [i.e. Canadian] Institute of Surveying and Mapping, Ottawa, Canada, February 27 to March 3, 1989. The Institute.
Cita Chicago (17th ed.)National Conference "GIS: Geographic Information Systems : Challenge for the 1990's" Ottawa, Canada, Mines and Resources Canada Canada. Energy, Canadian Association of Geographers, i Canadian Institute of Surveying and Mapping. GIS: Geographic Information Systems: Challenge for the 1990s = SIG: Systèmes D'information Géographique : Défi Des Années 90 : Proceedings, National Conference, Candian [i.e. Canadian] Institute of Surveying and Mapping, Ottawa, Canada, February 27 to March 3, 1989. Ottawa, Canada: The Institute, 1989.
Cita MLA (8th ed.)National Conference "GIS: Geographic Information Systems : Challenge for the 1990's" Ottawa, Canada, et al. GIS: Geographic Information Systems: Challenge for the 1990s = SIG: Systèmes D'information Géographique : Défi Des Années 90 : Proceedings, National Conference, Candian [i.e. Canadian] Institute of Surveying and Mapping, Ottawa, Canada, February 27 to March 3, 1989. The Institute, 1989.