To the east of the Chien Mountain, between 20.30 and 21.30 north latitude, is a pretty nation called Jo (Yaw). They are supposed to have been Chien, who in progress of time have become Burmese, speaking their language, although very corruptly, and adopting all their customs. These Jo generally pass for necromancers and sorcerers, and are for this reason feared by the Burmese, who dare no ill-treated them for fear of their revenging themselves by some enchantment.

Father Sangermano edited by John Jardine,
The Burmese Empire, 1884, p.43