Perhaps you should try some spelling variations:
cac thuc » cach thuc, cac thu, can thuc
te sach » toc sach
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va dinh » van dinh, va kinh, va tinh
dinh vi » dinh ve, dinh viet, dinh tri
cuu tre » cua tre, cau tren, cau treo
ve cac » va cac, vien cac
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: te sach y ((((van xay) or (nang x))) or (nang ma)) hoi. hieu ve cac thuc va dinh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y ((((van xay) OR (nang x))) OR (nang ma)) hoi. hieu ve cac thuc va dinh vi cuu tre.
• Adding a wildcard symbol may retrieve word variants: te sach y ((((van xay) or (nang x))) or (nang ma)) hoi. hieu ve cac thuc va dinh vi cuu tre*.