Motacilla is a genus of passerine birds commonly known as the wagtails in the family Motacillidae. 

Passeriformes, Passerina, passerina: Latin passerinus sparrow-like, (i.e. sparrow-sized) (passer sparrow).
Motacillidae, Motacilla: From Latin motacilla (“wagtail”).

1/ Citrine Wagtail (Chìa vôi đầu vàng, Motacilla citreola)
2/ White Wagtail (Chìa vôi trắng, Motacilla alba)
or Black-backed wagtail (Chìa vôi lưng đen, Motacilla alba lugens)
Black-backed wagtail or Kamchatka/Japanese pied wagtail, similar to M. a. yarrellii, but has a black eyestripe and white remiges; might have a claim to constitute a distinct species.

3/ Grey Wagtail (Chìa vôi núi, Motacilla cinerea)
4/ Western Yellow Wagtail (Motacilla flava, Chìa vôi vàng Phuong Tay)
5/ Eastern yellow wagtail (Motacilla tschutschensis, Chìa vôi vàng Phuong Dong)
The specific epithet tschutschensis is from the locality, the Chukchi Peninsula is eastern Russia.

6/ White-Browed Wagtail
or Large Pied Wagtail 
(Motacilla maderaspatensis)
Chìa vôi mày trắng

7/ Mekong Wagtail
(Motacilla samveasnae)