Perhaps you should try some spelling variations:
lang van » dang van, tang van, hoang van
hanh tai » thanh tai, hang tai, hinh tai
qua cac » cua cac
nang xa » nang x, lang xa, nang ma
han tai » hang tai, nhan tai, van tai
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 xa) or (lang van)) hoi. hieu qua cac hoc va ((hanh tai) OR (han tai)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky ((nang xa) OR (lang van)) hoi. hieu qua cac hoc va ((hanh tai) OR (han tai)) cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky ((nang xa) or (lang van)) hoi. hieu qua cac hoc va ((hanh tai) OR (han tai)) cua te*".