Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
danh dau » lanh dao, hang dau, danh tu
va trien » va truyen, va thiet, va tuyen
hieu va » lieu va
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
te sach » toc sach
y nang » ky nang, ly nang, v nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y nang ma hoa. ((hieu va) OR (hieu qua)) tham thuc va danh dau ((cua tre) or (va trien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang ma hoa. ((hieu va) OR (hieu qua)) tham thuc va danh dau ((cua tre) OR (va trien))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang ma hoa. ((hieu va) OR (hieu qua)) tham thuc va danh dau ((cua tre) or (va trien))*".