Perhaps you should try some spelling variations:
thieu nien » thien nhien
cua triet » cua viet, su triet, va triet
nien cac » vien cac, dien cac, bien cac
tu sach » thu sach, su sach, te sach
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
cac tao » cau tao, cac tro, cac tac
va dan » ca dan, va dao, va dau
dan va » doan va, dan ca, ban va
va cua » va chua, via cua, ca cua

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