Perhaps you should try some spelling variations:
su triet » su viet, ve triet
hanh cao » hanh cac, hanh cat, hanh cad
su tien » su kien, su hien, tu tieng
cam luc » cam xuc, cau luc
va hanh » van hanh, va thanh, va danh
sang ma » tang ma, nang ma, sang tao
hieu va » lieu va
ky sang » ky nang, ky dang, ky tang
sac ky » cac ky, sai ky
luc va » duc va, tuc va, loc va
ma hoi » mai hoi, xa hoi, ma hoa
so sac » so sach, so dac

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sac ky sang ma hoi. ((hieu va) OR (hieu qua)) cam luc va hanh cao ((su triet) or (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sac ky sang ma hoi. ((hieu va) OR (hieu qua)) cam luc va hanh cao ((su triet) OR (su tien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sac ky sang ma hoi. ((hieu va) OR (hieu qua)) cam luc va hanh cao ((su triet) or (su tien))".
• Adding a wildcard symbol may retrieve word variants: so sac ky sang ma hoi. ((hieu va) OR (hieu qua)) cam luc va hanh cao ((su triet) or (su tien))*.