Yellow-bellied prinia 
(Chiền chiện bụng vàng, Prinia flaviventris)
The yellow-bellied prinia is a species of bird in the family Cisticolidae.

Cisticoladae from Cisticola, which is from Ancient Greek kisthos, "rock-rose", and Latin colere, "to dwell". ... cisticola)
flaviventris: New Latin; from flāvus (“yellow”) +‎ venter (“belly”)