Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
van thanh » ban thanh, van tuan
vien cac » vien bach, vien dai, vien da
dieu cua » dieu tra
luc van » luoc van, luu van, duc van
cac luc » cau luc, coc luc, cac nuoc
nang o » nang co, nang ho, nang ro
sac ky » cac ky
te cua » tue cua, le cua, de cua
o hoc » co hoc, mo hoc, so hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sai ky) OR (sac ky)) nang o hoc. hieu vien cac luc van thanh ((dieu cua) or (te cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sai ky) OR (sac ky)) nang o hoc. hieu vien cac luc van thanh ((dieu cua) OR (te cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sai ky) OR (sac ky)) nang o hoc. hieu vien cac luc van thanh ((dieu cua) or (te cua)) tre".
• Adding a wildcard symbol may retrieve word variants: te ((sai ky) OR (sac ky)) nang o hoc. hieu vien cac luc van thanh ((dieu cua) or (te cua)) tre*.