Perhaps you should try some spelling variations:
hanh hai » thanh hai, nhanh hai, hang hai
su sach » so sach, vu sach
le manh » le minh, le thanh
hieu ve » hieu va, hieu van
cao duc » dao duc, cao suc, tao duoc
va hanh » van hanh, va thanh, va danh
hai va » hai van, thai va, hoi 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 manh) or (le anh)) xa hoi. hieu ve ((cao duc) OR (giao duc)) va hanh hai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((le manh) OR (le anh)) xa hoi. hieu ve ((cao duc) OR (giao duc)) va hanh hai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((le manh) or (le anh)) xa hoi. hieu ve ((cao duc) OR (giao duc)) va hanh hai va thiet".
• Adding a wildcard symbol may retrieve word variants: su sach ((le manh) or (le anh)) xa hoi. hieu ve ((cao duc) OR (giao duc)) va hanh hai va thiet*.