Perhaps you should try some spelling variations:
nuoc gia » nuoc giai, nuoc giao, quoc gia
thanh vi » thanh va, thanh ve, nhanh vi
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
vu sac » vu sach, vu san, va sac
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, me hoi
ve hoc » te hoc, va hoc, vi hoc

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: vu sac ky nang ((ma hoi) OR (ma hoa)). hieu ve hoc nuoc gia ((thanh vi) OR (hanh vi)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sac ky nang ((ma hoi) or (ma hoa)). hieu ve hoc nuoc gia ((thanh vi) OR (hanh vi)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: vu sac ky nang ((ma hoi) or (ma hoa)). hieu ve hoc nuoc gia ((thanh vi) OR (hanh vi)) cua tre*.