APA (7th ed.) Citation

Goelker, K. (2007). GIMP 2 for photographers: Image editing with open source software. Rocky Nook.

Chicago Style (17th ed.) Citation

Goelker, Klaus. GIMP 2 for Photographers: Image Editing with Open Source Software. Santa Barbara, CA: Rocky Nook, 2007.

MLA (8th ed.) Citation

Goelker, Klaus. GIMP 2 for Photographers: Image Editing with Open Source Software. Rocky Nook, 2007.