Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
sach kem » hanh kem
ban danh » ban doanh, ban hanh, ban dan
thuc ban » thuoc ban, thuc dan, thu ban
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cua triet, dua tren
danh vi » hanh vi, dinh vi, danh di
nang xa » nang x, lang xa, nang ma
cuu tre » cau tren, cau treo
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach kem) or (sac ky)) nang xa hoi. hieu van nam thuc ban danh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach kem) OR (sac ky)) nang xa hoi. hieu van nam thuc ban danh vi ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu ((sach kem) or (sac ky)) nang xa hoi. hieu van nam thuc ban danh vi ((cua tre) or (cuu tre))*.