Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
thuc dan » thuc hanh, hoc dan, thuc vat
dan hanh » dang hanh, dan khanh, dan thanh
su sach » so sach, vu sach
may hoi » may thoi, tay hoi, mai hoi
hieu ve » hieu va
ca viet » va viet, co viet, hoa viet
y mang » cay mang
vi ca » vit ca, li ca, va ca

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 mang may hoi. ((hieu ve) or (hieu van)) nam thuc dan hanh vi ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y mang may hoi. ((hieu ve) OR (hieu van)) nam thuc dan hanh vi ca viet.
• Adding a wildcard symbol may retrieve word variants: su sach y mang may hoi. ((hieu ve) or (hieu van)) nam thuc dan hanh vi ca viet*.