Perhaps you should try some spelling variations:
bo sach » co sach, hoc sach
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
hieu ve » hieu van
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, pham duc
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.

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