Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
nam thuc » nam thuoc, am thuc, nam thu
hieu va » lieu va, hieu qua
hieu ve » hieu van
su sach » so sach, vu sach
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
co sach » bo sach, cuon sach, hoc sach
ma hoi » mai hoi, xa hoi, ma hoa
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (co sach)) ky tang ma hoi. ((hieu ve) OR (hieu va)) nam thuc dan hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (co sach)) ky tang ma hoi. ((hieu ve) OR (hieu va)) nam thuc dan hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (co sach)) ky tang ma hoi. ((hieu ve) OR (hieu va)) nam thuc dan hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (co sach)) ky tang ma hoi. ((hieu ve) OR (hieu va)) nam thuc dan hanh vi cua viet*.