Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
lang van » dang van, tang van, hoang van
vien cac » vien bach, vien dai, vien da
nang xa » nang x, lang xa, nang ma
cac loc » cac lop, cac toc, cac hoc
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
loc va » hoc va, luc va
vi cua » vai cua, di cua

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 vien cac loc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky ((nang xa) OR (lang van)) hoi. hieu vien cac loc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: te sac ky ((nang xa) or (lang van)) hoi. hieu vien cac loc va hanh vi cua tre*.