Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
cua viet » ca viet, hoa viet, cua vat
hieu van » hieu va, thien van, lieu va
danh vai » danh sai, danh va, doanh van
van cham » van chat, van tham, va cham
lai hoi » dai hoi, lai hoa, mai hoi
lai roi » loi roi
mai doi » moi doi, mai hoi, mai khoi
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
vai cua » dai cua, hai cua, lai cua
so sach » so sanh, bo sach, co sach
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) OR (lai roi)))). hieu van cham thuc va danh 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) OR (lai roi)))). hieu van cham thuc va danh vai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y nang ((mai doi) or (((lai hoi) OR (lai roi)))). hieu van cham thuc va danh vai cua viet".
• Adding a wildcard symbol may retrieve word variants: so sach y nang ((mai doi) or (((lai hoi) OR (lai roi)))). hieu van cham thuc va danh vai cua viet*.