"[T]he Zappo-Zap people [were] a notorious group whose name probably came from the sound of gunfire. The Zappo-Zaps (a subgroup of the Songye people) were the chameleons of the Kasai region, who survived by imitating their European and Arab oppressors. Most notoriously, they worked as middlemen in the slave trade, abducting their neighbors and selling them to foreigners. The Belgian traders rewarded their best workers with wives, bought from the Zappo-Zaps for a few lengths of cloth."
* Kennedy 2002 p131
"At the turn of the century, the Belgians had just begun to despoil the Kasai, chopping down forests and burning villages in order to get at the precious rubber. ... [I]n September 1899, ... [t]he Zappo-Zaps had set about destroying an entire Kuba district. The massacre was unfolding only a short march away, in a region called Pianga. And rumor had it that Belgians had ordered the attack. They had hired the Zappo-Zaps to subdue the region and confiscate every last ball of rubber."
* Kennedy 2002 p136
"The Zappo-Zaps were hundreds strong, hardened from years of slave trading and armed with expensive European rifles."
* Spring 1993 p92
"[C]hiefs of the Songye people carry ceremonial axes with large, wrought iron blades rendered in openwork and often incorporating numberous small human heads, possibly symbolic of subordinate peoples. ... [T]he wooden hafts are sheathed entirely in copper. Though widely used amongst the Songye peoples, many of these axes were made by the Nsapo sub-group among whom there was a thriving iron-and copper-working industry."
* Benitez & Barbier eds. 2000 p88
"This well-known shield was probably made alongside similar Songye/Luba bifwebe masks (singular, kifwebe) in the southeastern border region of the Bena Gende. Dunja Herzsak, a specialist in the region, has written many informed articles about the striated bifwebe Songye masks and refers to their black-and-white stripes as being symbolic of animals, including bushbucks and zebras. ...
"These shields have a symbolic rather than a defensive function. Many of them are carved in softwood (ricinodendron) and were used like flags to lead troops into battle. Similar shields were used as gifts to chiefs who chose to align themselves with the Luba rather than fight."