Any sources on Northrop's "Black Widow Group"?

[uncannyexpeditions]

I've seen the designation "Black Widow Group" thrown around in some discussions particularly around the speculated Senior Citizen aircraft, with the implication being that it is/was some unacknowledged equivalent to Skunk Works at Northrop. I'm curious if there are any sources (official or otherwise) someone could link me to back up this groups existence, or at least something to trace the origin of the claims as there's very little info online.