Perhaps you should try some spelling variations:
te sach » toc sach
hieu va » lieu va, hieu qua
cao duc » dao duc, cao suc, giao duc
va hang » van hang, va nang, va lang
y nang » ky nang, ly nang, v nang
va cao » va cac, va co, va dao
cua tu » cua tuc, cua su, cua vu
cua cu » cua chu, cua cau, cua su
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: te sach y nang x hoi. hieu va cao duc va hang va ((((cua te) OR (cua tu))) OR (cua cu))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang x hoi. hieu va cao duc va hang va ((((cua te) OR (cua tu))) or (cua cu))~".
• Adding a wildcard symbol may retrieve word variants: te sach y nang x hoi. hieu va cao duc va hang va ((((cua te) OR (cua tu))) or (cua cu))*.