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

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 dai ((ve triet) OR (va trien))~.
• 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 dai ((ve triet) OR (va trien)).
• 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 dai ((ve triet) OR (va trien))".
• Adding a wildcard symbol may retrieve word variants: te sach ((tu nang) or (tru nang)) xa hoi. hieu va cao duc va hanh dai ((ve triet) OR (va trien))*.