Gaya APA

Gorr, W, L., Kurland, K, S. (2008). GIS tutorial update for arcGIS 9.3 / Welpen L. Gorr; Kresten S. Kurlaaaaaaaaand (^a1). Calipornia: ESRI Press.

Gaya MLA

Gorr, Wilpen, L.., Kurland, Kristen, S.. "GIS tutorial update for arcGIS 9.3 / Welpen L. Gorr; Kresten S. Kurlaaaaaaaaand". ^a1 Calipornia: ESRI Press, 2008. .