APA Citation

 Anon, E. (2005).  Photoshop for nature photographers: A workshop in a book.  Sybex.

Chicago Style Citation

 Anon, Ellen.  Photoshop for Nature Photographers: A Workshop in a Book.  Sybex, 2005.

MLA Citation

 Anon, Ellen.  Photoshop for Nature Photographers: A Workshop in a Book.  Sybex, 2005.

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