Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
cau luc » cau truc, cau phuc
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, dua tren
y nang » ly nang, v nang, may nang
ve cau » ke cau, va cau, ve cac
luc va » duc va, tuc va, loc 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 ((y nang) OR (ky nang)) xa hoi. hieu ve cau luc va hanh vi ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (ky nang)) xa hoi. hieu ve cau luc va hanh vi ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y nang) OR (ky nang)) xa hoi. hieu ve cau luc va hanh vi ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y nang) OR (ky nang)) xa hoi. hieu ve cau luc va hanh vi ((cua tre) or (cua triet))*.