Perhaps you should try some spelling variations:
thieu nien » thien nhien
nien cac » vien cac, dien cac, bien cac
su triet » su viet, su tien, ve triet
hanh vai » hanh vi, hanh va, hanh tai
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
va hanh » van hanh, va thanh, va danh
sach ky » sac ky, sach y, sach kem
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu

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