Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
van thanh » ban thanh, van tuan
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
khu cong » thu cong, thi cong, cuu cong
nuoc van » nuoc va, nuoc san, luoc van
hieu van » thien van, lieu va, hieu ve
cua tre » cua te, cuu tre, cua triet
tai cua » thai cua, tai cuc, tri cua
cong ha » cong hoa, dong ha, cong tac
hieu va » lieu va, hieu qua
su cao » cu cao, vu cao, su co
ha hoi » hoa hoi, ha noi, xa hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su cao) or (tu cac)) khu cong ha hoi. ((hieu va) or (hieu van)) cac nuoc van thanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su cao) OR (tu cac)) khu cong ha hoi. ((hieu va) OR (hieu van)) cac nuoc van thanh tai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((su cao) or (tu cac)) khu cong ha hoi. ((hieu va) or (hieu van)) cac nuoc van thanh tai cua tre*.