Perhaps you should try some spelling variations:
thieu nien » thien nhien
nien cac » vien cac, dien cac, bien cac
su triet » su tien, ve triet
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
cac tuc » cac toc, cac tu, cac tac
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
su viet » so viet
tuc va » thuc va, truc va, tuc xa
ma hoi » mai hoi, xa hoi, ma hoa

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 ma hoi. thieu nien cac tuc va hanh vi ((((su triet) or (su viet))) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ma hoi. thieu nien cac tuc va hanh vi ((((su triet) OR (su viet))) OR (va thiet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ma hoi. thieu nien cac tuc va hanh vi ((((su triet) or (su viet))) or (va thiet))*.