Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
dang xay » dang van, van xay
va thanh » gia thanh, ban thanh, va tinh
hieu va » lieu va
cac hoc » cach hoc, cac hop, bac hoc
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
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 sac ky ((nang x) or (dang xay)) hoi. ((hieu va) or (hieu qua)) cac hoc va thanh dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky ((nang x) OR (dang xay)) hoi. ((hieu va) OR (hieu qua)) cac hoc va thanh dai cua te.
• Adding a wildcard symbol may retrieve word variants: te sac ky ((nang x) or (dang xay)) hoi. ((hieu va) or (hieu qua)) cac hoc va thanh dai cua te*.