Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
hieu vien » hieu hien, thieu nien, hieu tieng
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
thu van » thuc van, thuy van, tu van
cua tre » cua te, cuu tre, cua triet
xay hoi » xa hoi, tay hoi, cay phoi
va xay » va xac
vi cua » vai cua, di cua
ky va » ly va, ke va, my va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu van ky va xay hoi. ((hieu vien) or (hieu viec)) cac nuoc ((va hanh) OR (va danh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu van ky va xay hoi. ((hieu vien) OR (hieu viec)) cac nuoc ((va hanh) OR (va danh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu van ky va xay hoi. ((hieu vien) or (hieu viec)) cac nuoc ((va hanh) OR (va danh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: thu van ky va xay hoi. ((hieu vien) or (hieu viec)) cac nuoc ((va hanh) OR (va danh)) vi cua tre*.