Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
va hanh » van hanh, va thanh, va danh
dao duc » giao duc, tao duoc
hieu va » lieu va, hieu qua
sach le » cach le, sach de, sach kem
hieu ve » hieu van
manh xa » manh xay, mang xa, manh ba
sach lo » sach dao, sach doi, sach hoi
dai va » mai va
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: su ((sach le) OR (sach lo)) manh xa hoi. ((hieu ve) or (hieu va)) dao duc va hanh dai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach le) OR (sach lo)) manh xa hoi. ((hieu ve) OR (hieu va)) dao duc va hanh dai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach le) OR (sach lo)) manh xa hoi. ((hieu ve) or (hieu va)) dao duc va hanh dai va thiet".
• Adding a wildcard symbol may retrieve word variants: su ((sach le) OR (sach lo)) manh xa hoi. ((hieu ve) or (hieu va)) dao duc va hanh dai va thiet*.