Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
thanh ve » hanh ve, thanh va, thanh vien
va thanh » gia thanh, ban thanh, va tinh
viec cac » vien cac, viec cua, viec lam
sach thu » sach thue, sach thieu, sach tham
va triet » va thiet, va trien, ve triet
sach ty » sach y, sach tu, xach tay
cac tac » cac toc, cac bac, cac dac
tac va » tac da, tac xa, tuc va
x hoi » o hoi, x ho, 5 hoi
ve va » ve van, te va, ke va

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((sach ty) OR (sach thu)) nang ((x hoi) or (xa hoi)). hieu viec cac tac va thanh ve va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((sach ty) OR (sach thu)) nang ((x hoi) OR (xa hoi)). hieu viec cac tac va thanh ve va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((sach ty) OR (sach thu)) nang ((x hoi) or (xa hoi)). hieu viec cac tac va thanh ve va triet".
• Adding a wildcard symbol may retrieve word variants: hoc ((sach ty) OR (sach thu)) nang ((x hoi) or (xa hoi)). hieu viec cac tac va thanh ve va triet*.