Perhaps you should try some spelling variations:
hang tai » hang va, dung tai
hanh tai » thanh tai, han tai, hinh tai
cua tre » cua te, cuu tre, cua triet
nang ma » sang ma, nang cao, mang may
tang ma » mang may, tang van
hieu va » lieu va, hieu qua
hac tuc » thac toc, thai tuc
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
va hac » van hac, va khac, va cac

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky ((nang ma) OR (tang ma)) hoi. hieu va hac tuc xa ((hanh tai) OR (hang tai)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky ((nang ma) or (tang ma)) hoi. hieu va hac tuc xa ((hanh tai) OR (hang tai)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: su sac ky ((nang ma) or (tang ma)) hoi. hieu va hac tuc xa ((hanh tai) OR (hang tai)) cua tre*.