Bulu (bum-bum) = 3 (Wider communication). Used as a LWC throughout the South region and also (less so) in the East. Chosen as the church language of the American Presbyterian Mission in circa 1887. It is still the official church language. Another important factor in the spread of Bulu is the pattern of intermarriage: many if not most Bulu women marry outside the Bulu community.
Glottolog
[bum] at ISO 639-3
[bum] at OLAC
[bum] at Odin
Wikipedia
PHOIBLE
Bulu at WALS
Wikidata