Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien dai » hien dai
cua tre » cua te, cua triet, dua tren
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
sach ty » sach y, sach tu, sach thu
cuu tre » cau tren, cau treo
nang xa » nang x, lang xa, nang ma
dai tu » dai thu, tai tu, mai tu
sai ky » sac ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ty) or (sai ky)) nang xa hoi. hieu vien dai tu va hanh di ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sai ky)) nang xa hoi. hieu vien dai tu va hanh di ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) or (sai ky)) nang xa hoi. hieu vien dai tu va hanh di ((cua tre) or (cuu tre))*.