Perhaps you should try some spelling variations:
hanh vai » hanh vi, hanh va, hanh tai
va hanh » van hanh, va thanh, va danh
cao duc » dao duc, giao duc, tao duoc
cao suc » cao su
sach le » sach de, sach lo, sach kem
hieu ve » hieu va, hieu van
tang xa » trang xa, tang ma, lang xa
cach le » cach de, cac le, cach ben
vai va » mai va, dai va, hai 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 (cach le)) tang xa hoi. hieu ve ((cao suc) or (cao duc)) va hanh vai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach le) OR (cach le)) tang xa hoi. hieu ve ((cao suc) OR (cao duc)) va hanh vai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach le) OR (cach le)) tang xa hoi. hieu ve ((cao suc) or (cao duc)) va hanh vai va thiet".
• Adding a wildcard symbol may retrieve word variants: su ((sach le) OR (cach le)) tang xa hoi. hieu ve ((cao suc) or (cao duc)) va hanh vai va thiet*.