If you use the quotes on a pair of words for example "humanist Gill" you will get substantially different returns to [humanist gill], in fact the brackets made no difference to not having them. The key, I think, is that the quotes will produce results where those words follow each other, albeit including between them any of the terms and short common words that google ignores like punctuation and of, and, the.

Tim

This is one I have written and it works on any site. You can select text from any page. When you press the 'search' button it will prompt you to type in a phrase, with the selected text already in the box. Just press 'OK' and a new window will open with Google search results.

javascript:void(function()%20{%20var%20href%20=%20window.location.hostname;
%20var%20query%20=%20prompt('Enter%20a%20search%20phrase:',%20window.getSelection());
%20if(!query)%20{%20return%20false;%20}%20window.open('http://www.google.com/search?q=site:'+href+'+'+encodeURIComponent(query));%20}());

If you prefer to stay in the same window however, use this one:

javascript:void(function()%20{%20var%20href%20=%20window.location.hostname;
%20var%20query%20=%20prompt('Enter%20a%20search%20phrase:',%20window.getSelection());
%20if(!query)%20{%20return%20false;%20}%20window.location.href%20=%20'http://www.google.com/search?q=site:'+href+'+'+encodeURIComponent(query);%20}());

Copy to a text file and make sure it is all on one line. Then simply bookmark it. Tested on Mac (Safari, Omniweb & Firefox).