Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
van hanh » van thanh, ban hanh, van anh
tru nang » tra nang, tri nang, truc nano
va hanh » va thanh, va danh, ban hanh
cao duc » dao duc, cao suc, giao duc
te sach » toc sach
tu nang » tu nong, tu nano, tu lang
hieu va » lieu va, hieu qua
va cao » va cac, va co, va dao
dai va » mai va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((tu nang) or (tru nang)) xa hoi. hieu va cao duc ((va hanh) OR (van hanh)) dai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((tu nang) OR (tru nang)) xa hoi. hieu va cao duc ((va hanh) OR (van hanh)) dai va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((tu nang) or (tru nang)) xa hoi. hieu va cao duc ((va hanh) OR (van hanh)) dai va triet".
• Adding a wildcard symbol may retrieve word variants: te sach ((tu nang) or (tru nang)) xa hoi. hieu va cao duc ((va hanh) OR (van hanh)) dai va triet*.