Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hanh doi » thanh doi, hanh noi, hang doi
hieu van » thien van, lieu va, hieu ve
ly nang » ky nang, ly hang, ly vang
nang ma » tang ma, sang ma, nang cao
te sach » toc sach
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
doi cua » dai cua, hoi cua
tu sach » thu sach, su sach, tu cach
ma hoi » mai hoi, xa hoi, ma hoa

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ly nang ma hoi. ((hieu van) OR (hieu va)) am thuc va hanh doi cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) ly nang ma hoi. ((hieu van) or (hieu va)) am thuc va hanh doi cua viet~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (te sach)) ly nang ma hoi. ((hieu van) or (hieu va)) am thuc va hanh doi cua viet*.