http://www.google.com/search?
as_q=test (query string)
&hl=en (language)
&num=10 (number of results [10,20,30,50,100])
&btnG=Google+Search
&as_epq= (complete phrase)
&as_oq= (at least one)
&as_eq= (excluding)
&lr= (language results. [lang_countrycode])
&as_ft=i (filetype include or exclude. [i,e])
&as_filetype= (filetype extension)
&as_qdr=all (date [all,M3,m6,y])
&as_nlo= (number range, low)
&as_nhi= (number range, high)
&as_occt=any (terms occur [any,title,body,url,links])
&as_dt=i (restrict by domain [i,e])
&as_sitesearch= (restrict by [site])
&as_rights= (usage rights [cc_publicdomain,cc_attribute,cc_sharealike,cc_noncommercial,cc_nonderived]
&safe=images (safesearch [safe=on,images=off])
&as_rq= (similar pages)
&as_lq= (pages that link)
&gl=us (2-digit country code in lowercase)