Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
van thanh » ban thanh, van tuan
tai cua » thai cua, tai cuc, tri cua
duc van » duc va, duc tan, duc manh
cac duc » cac du, cao duc, cac dac
qua cac » cua cac
lang xa » lang ha, dang xay, lang van
tang ma » mang may, tang van
sach tu » sach thu, cach tu, sach ty
cua tre » cua te, cuu tre, cua triet

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) or (sach tu)) ((tang ma) or (lang xa)) hoi. hieu qua cac duc van thanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach y) OR (sach tu)) ((tang ma) OR (lang xa)) hoi. hieu qua cac duc van thanh tai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu ((sach y) or (sach tu)) ((tang ma) or (lang xa)) hoi. hieu qua cac duc van thanh tai cua tre*.