Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thuc dan » thuc hanh, hoc dan, thuc vat
nam thuc » nam thuoc, am thuc, nam thu
dang xay » dang van, van xay
dan dau » danh dau, doan dau, van dau
sach ty » sach y, sach tu, sach thu
hieu va » hieu qua
lang xa » lang ha, lang van
cuu tre » cua tre, cau tren, cau treo
dau va » dau ve, lau va
va cuu » va cau, va chu, va huu

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 ty ((lang xa) or (dang xay)) hoi. ((hieu va) or (lieu va)) nam thuc dan dau va cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty ((lang xa) OR (dang xay)) hoi. ((hieu va) OR (lieu va)) nam thuc dan dau va cuu tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ty ((lang xa) or (dang xay)) hoi. ((hieu va) or (lieu va)) nam thuc dan dau va cuu tre*.