Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
cao hoi » cau hoi, co hoi, cao hoc
va hanh » van hanh, va thanh, va danh
hanh ki » hanh vi, hanh ky, hanh kien
sac ky » cac ky, sai ky
va cam » va cham, va cac, va cai
va cao » va cac, va co, va dao
ki su » ky su

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

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