Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
toc sach » hoc sach, doc sach, thuoc sach
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
va hanh » van hanh, va thanh, va danh

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) or (toc sach)) ky nang xa hoi. hieu va cac duc va hanh vi ((cua triet) OR (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (toc sach)) ky nang xa hoi. hieu va cac duc va hanh vi ((cua triet) OR (va triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (toc sach)) ky nang xa hoi. hieu va cac duc va hanh vi ((cua triet) OR (va triet))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (toc sach)) ky nang xa hoi. hieu va cac duc va hanh vi ((cua triet) OR (va triet))*.