Enable Proximity Searching in Acrobat
When running an advanced search in Adobe Acrobat, note that you have the option to run proximity searches.
This option will be greyed out until the option in the 'Return results containing' menu for 'Match All of the words' is selected. When entering the search terms, separate them only with whitespaces, not with commas or anything else.
. . . note that the search results will be sorted by relevancy.
Under Edit . . . Preferences . . . Search . . . you can set the range for proximity searches.
For some reason, Adobe has set the default at a very high 900 words!