fileType property

Restricts results to files of a specified extension.

Filetypes supported by Google include: * Adobe Portable Document Format (pdf) * Adobe PostScript (ps) * Lotus 1-2-3 (wk1, wk2, wk3, wk4, wk5, wki, wks, wku) * Lotus WordPro (lwp) * Macwrite (mw) * Microsoft Excel (xls) * Microsoft PowerPoint (ppt) * Microsoft Word (doc) * Microsoft Works (wks, wps, wdb) * Microsoft Write (wri) * Rich Text Format (rtf) * Shockwave Flash (swf) * Text (ans, txt). Additional filetypes may be added in the future. An up-to-date list can always be found in Google's file type FAQ.