Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
sach nay » sach hay, sach vay, sach nang
vat cuu » vat cua
dan vat » dang vat, van vat, dan va
thuc ca » thuc cua, thuc can, thuc cao
hieu va » hieu qua
lang xa » dang xay, lang van
lang ha » long ha
cuu tre » cua tre, cau tren, cau treo
ca dan » cac dan, ca dao

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 nay ((lang xa) or (lang ha)) hoi. ((hieu va) OR (lieu va)) nam thuc ca dan vat cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach nay ((lang xa) OR (lang ha)) hoi. ((hieu va) OR (lieu va)) nam thuc ca dan vat cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach nay ((lang xa) or (lang ha)) hoi. ((hieu va) OR (lieu va)) nam thuc ca dan vat cuu tre*".