Perhaps you should try some spelling variations:
hanh dao » lanh dao, thanh dat, thanh dam
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
dao cuu » dao huu, dao cau, dao chu
ty ang » ty xang, ty hang, ty anh
ang xa » lang xa, mang xa, dang xay
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty ang xa hoi. ((hieu ve) or (hieu qua)) cau ((thuc va) or (hoc dan)) hanh dao cuu thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ang xa hoi. ((hieu ve) OR (hieu qua)) cau ((thuc va) OR (hoc dan)) hanh dao cuu thiet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty ang xa hoi. ((hieu ve) or (hieu qua)) cau ((thuc va) or (hoc dan)) hanh dao cuu thiet*.