Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
hieu van » hieu va, thien van, lieu va
thuc van » thuc vat, thuc dan, thuc va
mang xa » mang may, dang xay, mang cua
hanh ve » hanh vi, hanh va, hanh kem
lang xa » lang ha, dang xay, lang van
su sac » su sach, su cac, su xac
anh ve » anh va, anh viet, thanh ve
sac ky » cac ky, sai ky
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ky ((mang xa) or (lang xa)) hoi. hieu van nam thuc van ((anh ve) OR (hanh ve)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky ((mang xa) OR (lang xa)) hoi. hieu van nam thuc van ((anh ve) OR (hanh ve)) cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky ((mang xa) or (lang xa)) hoi. hieu van nam thuc van ((anh ve) OR (hanh ve)) cua te*".