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