Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
nam thuc » nam thuoc, am thuc, nam thu
hieu van » thien van, lieu va, hieu ve
thu sach » thuat sach, thuoc sach, thu hoach
lo nang » ho nang, ly nang, loai nang
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
danh de » hanh de, dan de, dang de
tu sach » su sach, te sach, tu cach
ma hoi » mai hoi, xa hoi, ma hoa
de cua » le cua, te cua, dieu cua

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 (thu sach)) lo nang ma hoi. ((hieu van) OR (hieu va)) nam thuc va danh de cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) lo nang ma hoi. ((hieu van) or (hieu va)) nam thuc va danh de cua viet~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) lo nang ma hoi. ((hieu van) or (hieu va)) nam thuc va danh de cua viet*.