APA (7th ed.) Citation

Clemmer, G. (2010). The GIS 20 : essential skills / Gina Clemmer: Essential skills. ESRI Press : Distributed to the trade by Ingram Publisher Service.

Chicago Style (17th ed.) Citation

Clemmer, Gina. The GIS 20 : Essential Skills / Gina Clemmer: Essential Skills. Redlands, Calif.: ESRI Press : Distributed to the trade by Ingram Publisher Service, 2010.

MLA (9th ed.) Citation

Clemmer, Gina. The GIS 20 : Essential Skills / Gina Clemmer: Essential Skills. ESRI Press : Distributed to the trade by Ingram Publisher Service, 2010.

Warning: These citations may not always be 100% accurate.