Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
dang xay » dang van, van xay
nam thuc » nam thuoc, am thuc, nam thu
thuc va » thuc vat, thuc dan, thuc day
sach ty » sach y, sach tu, sach thu
hieu va » hieu qua
lang xa » lang ha, lang van
cau tre » cau tren, cau treo, cau tra
va dau » va dao
dau va » dau ve, lau va
va cau » van cau, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ty ((lang xa) or (dang xay)) hoi. ((hieu va) or (lieu va)) nam thuc va dau va cau tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ty ((lang xa) OR (dang xay)) hoi. ((hieu va) OR (lieu va)) nam thuc va dau va cau tre.
• Adding a wildcard symbol may retrieve word variants: hoc sach ty ((lang xa) or (dang xay)) hoi. ((hieu va) or (lieu va)) nam thuc va dau va cau tre*.