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
cua tre » cuu tre, cua triet, dua tren
dac ban » cac ban, dac san, duc ban
cac dac » cac dan, cac dai, cac bac
van cac » van hac, van cau, van bac
tu sach » thu sach, su sach, te sach
ly hang » ly quang
ly nang » ky nang, ly vang, ly quang
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 ((ly nang) OR (ly hang)) x hoi. hieu van cac dac ban thanh dai ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ly nang) OR (ly hang)) x hoi. hieu van cac dac ban thanh dai ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ly nang) OR (ly hang)) x hoi. hieu van cac dac ban thanh dai ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ly nang) OR (ly hang)) x hoi. hieu van cac dac ban thanh dai ((cua tre) or (cua te))*.