The following Google serches for backlinks all return different results. Which one (or any other) would Google use to

find backlinks to our website in order to calculate one's website pagerank?

link:siteretriever(dot)com - Returns: 0,1,4 (the result varies)
link: siteretriever(dot)com - Returns 677.000
link:www(dot)siteretriever(dot)com - Returns: 0,1 (the result varies)
link: www(dot)siteretriever(dot)com - Returns: 2.850
link:http(double dot)//www(dot)siteretriever(dot)com - Returns: 0,1,4 (the result varies)
link: http(double dot)//www(dot)siteretriever(dot)com - Returns: 1.480
href="http(double dot)//www(dot)siteretriever(dot)com" - Returns: 229
"http(double dot)//www(dot)siteretriever(dot)com" - Returns: 772
http(double dot)//www(dot)siteretriever(dot)com - Returns: 731


The online free services for counting backlinks also return different results and some of them are not even close to

some of the above...

Any idea?