Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
te sach » toc sach
hanh de » hanh ve, hanh kem
hanh di » hanh vi, hang di, danh di
thuc va » thuc vat, thuc dan, thuc day
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
va cam » va cham, va cac, va cao

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 ty ((nang xa) OR (nang ma)) hoi. hieu va cam thuc va ((hanh di) or (hanh de)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty ((nang xa) OR (nang ma)) hoi. hieu va cam thuc va ((hanh di) OR (hanh de)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((nang xa) OR (nang ma)) hoi. hieu va cam thuc va ((hanh di) or (hanh de)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty ((nang xa) OR (nang ma)) hoi. hieu va cam thuc va ((hanh di) or (hanh de)) cua tre*.