Any search term that you want to guarantee is on the page must have a + prefix. You tend to get pages with ALL the words you specify because of the kind of matching Google does, but not confuse that with AND.
According to Google's help file, they use AND by default:
Automatic "and" queries
By default, Google only returns pages that include all of your search terms. There is no need to include "and" between terms. Keep in mind that the order in which the terms are typed will affect the search results. To restrict a search further, just include more terms. For example, to plan a vacation to Hawaii, simply type vacation hawaii.