Google-search – Why does Google News not include the search

Weirdly, it seems that by simply repeating words in the Google search box it will give more weight to them (or at least look for more instances of them on the page).

Try:
elephant galaxy calculator netball
compared with:
elephant galaxy calculator calculator netball

So, you could try:
resize resize image image bookmarklet bookmarklet chrome

'Google Hacks (2003 version)' - see the section 'Repetition matters' - suggests that Google looks for at least the number of instances of a keyword that you supply.

Also, the order of words in the query makes a difference...
Compare:
resize image bookmarklet chrome
to:
chrome resize image bookmarklet
the latter seems to give more emphasis to 'chrome' in the results.

It's interesting that if you remove ~ullman from the site you get your first result returned at the very top of the search results again!

 site:http://infolab.stanford.edu/ filetype:pdf view serializability

Browsing around Professor Ullman's page, I noticed that there were no (live) direct links to the original vs-old.pdf file that was at the top of your original search. I'm guessing that if you are restricting results to Professor Ullman's section of the infolab site, there will be no results returned, whereas there are likely to be other pages in the infolab that contain links to that particular document - which results in that pdf reappearing when submitting a less restrictive search.