Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
nang cai » nang cao, nang tai, nang cap
sach ky » sach y, sach ty, sach kem
vai cua » dai cua, hai cua, lai cua
va dinh » van dinh, va kinh, va tinh
va hanh » van hanh, va thanh, va danh
qua cac » cua cac
cai hoi » cau hoi, dai hoi, cai hoa
cac luc » cau luc, coc luc, cac nuoc
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: su ((sach ky) OR (sac ky)) nang cai hoi. hieu qua cac luc ((va hanh) or (va dinh)) vai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sac ky)) nang cai hoi. hieu qua cac luc ((va hanh) OR (va dinh)) vai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sac ky)) nang cai hoi. hieu qua cac luc ((va hanh) or (va dinh)) vai cua triet".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sac ky)) nang cai hoi. hieu qua cac luc ((va hanh) or (va dinh)) vai cua triet*.