Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
cac dac » cac dan, cac bac, cac tac
cac dai » cac dan, cac bai, can dai
cua tre » cuu tre, cua triet, dua tren
y nang » ky nang, ly nang, v nang
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: tu sach y nang x hoi. hieu van ((cac dac) or (cac dai)) ban thanh dai ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang x hoi. hieu van ((cac dac) OR (cac dai)) ban thanh dai ((cua tre) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: tu sach y nang x hoi. hieu van ((cac dac) or (cac dai)) ban thanh dai ((cua tre) or (cua te))*.