Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
hieu van » thien van, lieu va, hieu ve
sach tu » sach thu, cach tu, sach ty
cam duc » cam xuc, cao duc, nam duoc
hieu va » lieu va, hieu qua
tu nang » tru nang, tu nong, tu nano
nang o » nang co, nang ho, nang ro
vi cua » vai cua, di cua
cua te » cua tu
o hoi » co hoi, o hoc, o hai

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 tu nang o hoi. ((hieu van) or (hieu va)) ((cam duc) OR (pham duc)) va thanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach tu nang o hoi. ((hieu van) OR (hieu va)) ((cam duc) OR (pham duc)) va thanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach tu nang o hoi. ((hieu van) or (hieu va)) ((cam duc) OR (pham duc)) va thanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: hoc sach tu nang o hoi. ((hieu van) or (hieu va)) ((cam duc) OR (pham duc)) va thanh vi cua te*.