You might be able to do it by adding the required word Discourse to the search, like so:
albacore
versus
albacore +Discourse
The plus sign means it is a required word for the search to be valid. Except.. Google removed support for this in 2011. 
You might be able to do it by adding the required word Discourse to the search, like so:
albacore
versus
albacore +Discourse
The plus sign means it is a required word for the search to be valid. Except.. Google removed support for this in 2011.