Perhaps you should try some spelling variations:
thuc day » thuc dan, thuc vat
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan
co viet » so viet, o viet, hoc viet
hieu va » lieu va, hieu qua
hieu ve » hieu van
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
vi co » vi con, voi co, vi mo

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky tang ma hoa. ((hieu ve) or (hieu va)) nam ((thuc va) or (thuc day)) hanh vi co viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky tang ma hoa. ((hieu ve) OR (hieu va)) nam ((thuc va) OR (thuc day)) hanh vi co viet.
• Adding a wildcard symbol may retrieve word variants: vu sach ky tang ma hoa. ((hieu ve) or (hieu va)) nam ((thuc va) or (thuc day)) hanh vi co viet*.