Perhaps you should try some spelling variations:
day danh » day manh, dai danh, dao danh
thuc day » thuc dan, thuc vat
nam thuc » nam thuoc, am thuc, nam thu
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
vai cua » dai cua, hai cua, lai cua
su sach » so sach, vu sach
va nam » van nam, ha nam, va nay
vai ca » vai cac, bai ca, vai va

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y ((nang ma) or (nang x)) hoi. hieu va nam thuc day danh ((vai ca) or (vai cua)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((nang ma) OR (nang x)) hoi. hieu va nam thuc day danh ((vai ca) OR (vai cua)) tren.
• Adding a wildcard symbol may retrieve word variants: su sach y ((nang ma) or (nang x)) hoi. hieu va nam thuc day danh ((vai ca) or (vai cua)) tren*.