Perhaps you should try some spelling variations:
thanh thai » thanh hai, nhanh thai, thanh thao
thanh tai » thanh hai, thanh toan, doanh tai
dang xay » dang van, van xay
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
cac hoc » cach hoc, cac hop, bac hoc
hoc gia » hoc giao, hoc giai, toc gia
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 xa) or (dang xay)) hoi. hieu va cac hoc gia ((thanh thai) OR (thanh tai)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky ((nang xa) OR (dang xay)) hoi. hieu va cac hoc gia ((thanh thai) OR (thanh tai)) cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky ((nang xa) or (dang xay)) hoi. hieu va cac hoc gia ((thanh thai) OR (thanh tai)) cua te".
• Adding a wildcard symbol may retrieve word variants: te sac ky ((nang xa) or (dang xay)) hoi. hieu va cac hoc gia ((thanh thai) OR (thanh tai)) cua te*.