Perhaps you should try some spelling variations:
thieu nien » thien nhien
nien cac » vien cac, dien cac, bien cac
ve triet » va trien, su triet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cac luc » cau luc, coc luc, cac nuoc
va hang » van hang, va nang, va hanh
va lang » va nang, hoa lang
x hoi » xa hoi, o hoi, x ho

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