Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh doi » thanh doi, hanh noi, hang doi
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
cua tre » cuu tre, cua triet, dua tren
te sach » toc sach
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
van am » van nam, van lam, van dam
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y ((nang ma) or (sang ma)) hoi. hieu van am thuc dan hanh doi ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y ((nang ma) OR (sang ma)) hoi. hieu van am thuc dan hanh doi ((cua tre) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: te sach y ((nang ma) or (sang ma)) hoi. hieu van am thuc dan hanh doi ((cua tre) or (cua te))*.