Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
sach doi » sach hoi, sach moi, sach dao
hieu van » thien van, lieu va, hieu ve
doi nang » dai nang, hoi nang, voi nang
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
tu sach » thu sach, su sach, te sach
ma hoi » mai hoi, ma hoa, me hoi
di cua » dai cua, doi cua, de cua

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 doi nang ((ma hoi) or (xa hoi)). ((hieu van) or (hieu va)) am thuc va hanh di cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach doi nang ((ma hoi) OR (xa hoi)). ((hieu van) OR (hieu va)) am thuc va hanh di cua viet.
• Adding a wildcard symbol may retrieve word variants: tu sach doi nang ((ma hoi) or (xa hoi)). ((hieu van) or (hieu va)) am thuc va hanh di cua viet*.