Perhaps you should try some spelling variations:
thien van » thi van
hieu van » hieu va, lieu va, hieu ve
hanh tai » thanh tai, hang tai, han tai
so sach » so sanh, bo sach, co sach
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
va hanh » van hanh, va thanh, va danh
cua tu » cua tuc, cua su, cua cu
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach tu nang x hoi. ((hieu van) OR (thien van)) pham duc va hanh tai ((cua te) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach tu nang x hoi. ((hieu van) OR (thien van)) pham duc va hanh tai ((cua te) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach tu nang x hoi. ((hieu van) OR (thien van)) pham duc va hanh tai ((cua te) or (cua tu))".
• Adding a wildcard symbol may retrieve word variants: so sach tu nang x hoi. ((hieu van) OR (thien van)) pham duc va hanh tai ((cua te) or (cua tu))*.