Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
hanh vai » hanh vi, hanh va, hanh tai
cua viet » ca viet, hoa viet, cua vat
so sach » so sanh, bo sach, co sach
mai doi » moi doi, mai hoi, mai khoi
lai hoi » dai hoi, lai hoa, lai roi
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
vai cua » dai cua, hai cua, lai cua
y nang » ky nang, ly nang, v nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y nang ((mai doi) or (lai hoi)). hieu van cham thuc va hanh vai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y nang ((mai doi) OR (lai hoi)). hieu van cham thuc va hanh vai cua viet.
• Adding a wildcard symbol may retrieve word variants: so sach y nang ((mai doi) or (lai hoi)). hieu van cham thuc va hanh vai cua viet*.