Perhaps you should try some spelling variations:
su triet » su viet, ve triet
hanh de » hanh ve, hanh kem
va hanh » van hanh, va thanh, va danh
va pham » van pham, va phat, va phap
sach ky » sac ky, sach y, sach kem
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
sach ty » sach y, sach tu, sach thu
su tien » su kien, su hien, tu tieng
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: vu ((sach ky) or (sach ty)) nang ma hoi. hieu va pham duc va hanh de ((su triet) or (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu ((sach ky) OR (sach ty)) nang ma hoi. hieu va pham duc va hanh de ((su triet) OR (su tien)).
• Adding a wildcard symbol may retrieve word variants: vu ((sach ky) or (sach ty)) nang ma hoi. hieu va pham duc va hanh de ((su triet) or (su tien))*.