Perhaps you should try some spelling variations:
thanh vien » nhan vien, thanh van
thanh ve » hanh ve, thanh va, thanh van
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
qua cac » cua cac
cac tac » cac toc, cac bac, cac dac
cua tre » cua te, cuu tre, cua triet
tac va » tac da, tac xa, tuc va

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 ky tang xa hoi. hieu qua cac tac va ((thanh ve) or (thanh vien)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky tang xa hoi. hieu qua cac tac va ((thanh ve) OR (thanh vien)) cua tre.
• Adding a wildcard symbol may retrieve word variants: so sach ky tang xa hoi. hieu qua cac tac va ((thanh ve) or (thanh vien)) cua tre*.