Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thu sach » tu sach, thuat sach, thuoc sach
van nang » van quang, van ban, van dong
hieu van » hieu va, thien van, lieu va
nam duc » nam duoc, pham duc, nam thuc
y nang » ky nang, ly nang, v nang
va dan » ca dan, va dau, va dap
va dao » ca dao

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

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