Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
toc sach » hoc sach, doc sach, thuoc sach
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
van hoe » van hoc, van hieu, van hien
hieu va » hieu qua
cuu tre » cua tre, cau tren, cau treo
vi cuu » vi luu, vinh cuu

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 _ lang ((van hoe) OR (van hoa)). ((hieu va) or (lieu va)) tham thuc van hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach _ lang ((van hoe) OR (van hoa)). ((hieu va) OR (lieu va)) tham thuc van hanh vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach _ lang ((van hoe) OR (van hoa)). ((hieu va) or (lieu va)) tham thuc van hanh vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: toc sach _ lang ((van hoe) OR (van hoa)). ((hieu va) or (lieu va)) tham thuc van hanh vi cuu tre*.