Perhaps you should try some spelling variations:
hanh doi » thanh doi, hanh noi, hang doi
nam thuc » nam thuoc, am thuc, nam thu
tu sach » thu sach, su sach, te sach
sach lo » sach dao, sach doi, sach hoi
ca viet » va viet, hoa viet, san viet
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu va, hieu van
tang ma » mang may, tang van
lo tang » le tang, do tang, lo tan
co viet » so viet, o viet, hoc viet
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 lo tang ma hoi. ((hieu ve) OR (hieu qua)) nam thuc va hanh doi ((ca viet) OR (co viet))~.
• Adding a wildcard symbol may retrieve word variants: tu sach lo tang ma hoi. ((hieu ve) or (hieu qua)) nam thuc va hanh doi ((ca viet) or (co viet))*.