Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
va thanh » gia thanh, ban thanh, va tinh
su sach » vu sach
so sach » so sanh, bo sach, co sach
le tang » le quang, le trung, le thanh
tang xa » trang xa, tang ma, lang xa
suc va » duc va, tuc va, luc va
ve cao » ve bao, ve cac, ve co
va cao » va cac, va co, va dao
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) OR (so sach)) le tang xa hoi. hieu ((ve cao) or (va cao)) suc va thanh vai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) le tang xa hoi. hieu ((ve cao) OR (va cao)) suc va thanh vai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (so sach)) le tang xa hoi. hieu ((ve cao) or (va cao)) suc va thanh vai va thiet".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (so sach)) le tang xa hoi. hieu ((ve cao) or (va cao)) suc va thanh vai va thiet*.