I may have missed it, but did you list 1e Unearthed Arcana? The Barbarian class had some info on the different "barbarian" cultures of Greyhawk.
I can't recall if the Greyhawk information for the Barbarian also appeared in Dragon #63 which was the first appearance of the class that appeared in UA.
I can't recall if the Greyhawk information for the Barbarian also appeared in Dragon #63 which was the first appearance of the class that appeared in UA.