Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
sach tu » sach thu, cach tu, sach uu
sach ty » sach y, sach thu, xach tay
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, pham duc
va hanh » van hanh, va thanh, va danh
vi cua » vai cua, di cua
cua te » cua tu
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: bo ((sach tu) OR (sach ty)) nang x hoi. ((hieu van) or (hieu va)) cam duc va hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo ((sach tu) OR (sach ty)) nang x hoi. ((hieu van) OR (hieu va)) cam duc va hanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "bo ((sach tu) OR (sach ty)) nang x hoi. ((hieu van) or (hieu va)) cam duc va hanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: bo ((sach tu) OR (sach ty)) nang x hoi. ((hieu van) or (hieu va)) cam duc va hanh vi cua te*.