Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien dai » hien dai
thuc van » thuc dan, thuc va, hoc van
su sach » so sach, vu sach
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
nang xa » nang x, lang xa, nang ma
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua

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 tu nang xa hoi. hieu vien dai ((((thuc van) or (thuc hanh))) or (thuc vat)) hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu nang xa hoi. hieu vien dai ((((thuc van) OR (thuc hanh))) OR (thuc vat)) hanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach tu nang xa hoi. hieu vien dai ((((thuc van) or (thuc hanh))) or (thuc vat)) hanh di cua tre*.