It seems that it’s not possible anymore to combine two negative “source” operators, or a “source” with an “include” operator.
This means that the following are no longer valid search strings:
sometext -source:A -source:B
sometext -source:A -include:retweets
…which means that we can no longer drop automated tweets (created via specific applications “source”) from our search results.
Has something changed in the search API?