Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
thu sach » thuat sach, thuoc sach, thu hoach
thi nang » thi cong, ki nang, thi hanh
nang lai » nang tai, mang lai, nang cai
cao duc » dao duc, cao suc, giao duc
va danh » va dinh, va hanh, dia danh
tu sach » su sach, te sach, tu cach
hieu va » lieu va, hieu qua
lai roi » lai hoi, loi roi
va cao » va cac, va co, va dao
va dan » ca dan, va dao, va dau
vai va » mai va, dai va, hai va

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) OR (thu sach)) thi nang lai roi. hieu va cao duc ((va danh) or (va dan)) vai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) thi nang lai roi. hieu va cao duc ((va danh) OR (va dan)) vai va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) thi nang lai roi. hieu va cao duc ((va danh) or (va dan)) vai va triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) thi nang lai roi. hieu va cao duc ((va danh) or (va dan)) vai va triet*.