Perhaps you should try some spelling variations:
thieu nien » thien nhien
thanh tai » thanh hai, thanh toan, doanh tai
nien cac » vien cac, dien cac, bien cac
su triet » su viet, su tien, ve triet
va thanh » gia thanh, ban thanh, va tinh
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
sach ky » sach y, sach ty, sach kem
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
sac ky » cac ky, sai ky

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ky) or (sac ky)) nang ma hoi. thieu nien cac nuoc va thanh tai ((su triet) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sac ky)) nang ma hoi. thieu nien cac nuoc va thanh tai ((su triet) OR (va thiet)).
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) or (sac ky)) nang ma hoi. thieu nien cac nuoc va thanh tai ((su triet) or (va thiet))*.