Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
hanh tai » hang tai, han tai, hinh tai
hoc cac » hoc cao
cac tuc » cac toc, cac tu, cac tac
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
cua hoi » cua moi
ly hang » ly quang
cac ly » cac ky, cac le, cam ly
ca hoi » cau hoi, xa hoi, co hoi
ve cac » va cac, vien cac

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc cac ly hang ((ca hoi) OR (cua hoi)). hieu ve cac tuc xa ((hanh tai) or (thanh tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc cac ly hang ((ca hoi) OR (cua hoi)). hieu ve cac tuc xa ((hanh tai) OR (thanh tai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc cac ly hang ((ca hoi) OR (cua hoi)). hieu ve cac tuc xa ((hanh tai) or (thanh tai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc cac ly hang ((ca hoi) OR (cua hoi)). hieu ve cac tuc xa ((hanh tai) or (thanh tai)) cua tre*.