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
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
cao hoi » cau hoi, cao hoc, tao hoi
hai cau » hai chau, hai chu, hai hau
hai chi » thai chi, tai chi, hai thi
tu sach » thu sach, su sach, te sach
co hoi » co hoc, co loi
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: tu sach y nang ((cao hoi) or (co hoi)). hieu van cham thuc va hanh ((hai cau) or (hai chi)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((cao hoi) OR (co hoi)). hieu van cham thuc va hanh ((hai cau) OR (hai chi)) treo.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((cao hoi) or (co hoi)). hieu van cham thuc va hanh ((hai cau) or (hai chi)) treo*.