Upson, S. A Global Search Engine For Geospatial Data. IEEE spectrum.
Cita Chicago (17th ed.)Upson, S. "A Global Search Engine For Geospatial Data." IEEE Spectrum .
Cita MLA (9th ed.)Upson, S. "A Global Search Engine For Geospatial Data." IEEE Spectrum, .
Atenció: Aquestes cites poden no estar 100% correctes.