Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
cua viet » ca viet, hoa viet, cua vat
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
ly nang » ky nang, ly hang, ly vang
van cac » van hac, van cau, van bac
y nang » ky nang, v nang, may nang
va dan » ca dan, va dao, va dau
dan va » doan va, dan ca, ban va
he va » che va, he van, te va

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ((y nang) or (ly nang)) xa hoi. hieu van cac he va dan va ((cua viet) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((y nang) OR (ly nang)) xa hoi. hieu van cac he va dan va ((cua viet) OR (va triet)).
• Adding a wildcard symbol may retrieve word variants: so sach ((y nang) or (ly nang)) xa hoi. hieu van cac he va dan va ((cua viet) or (va triet))*.