Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
toc sach » hoc sach, doc sach, thuoc sach
vien cac » vien bach, vien dai, vien da
thuc day » thuc dan
hang dau » hang va, hang tai
lang xa » lang ha, dang xay, lang van
dau cua » dai cua, day cua, cau cua
cua tre » cua te, cuu tre, cua triet
y lang » o lang, _ lang, tay lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach y lang xa hoi. hieu vien cac ((thuc day) or (thuc vat)) hang dau cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y lang xa hoi. hieu vien cac ((thuc day) OR (thuc vat)) hang dau cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach y lang xa hoi. hieu vien cac ((thuc day) or (thuc vat)) hang dau cua tre*.