Super Search allows you to specify a phrase, url, or other kind of target and to specify an author. Note the option to include a definition of "(separate strings with -- default is spaces) and -- of course -- the areas to search.
HTH. Seems to me a starting point, though you may have to wash-rinse-repeat with different flavors of soap (search terms) to be confident you haven't missed anything.
If I've misconstrued your question or the logic needed to answer it, I offer my apologies to all those electrons which were inconvenienced by the creation of this post.