Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
sach ky » sac ky, sach ty, sach kem
cao tuc » dao tuc, cao suc, cao toc
cao duc » dao duc, cao suc, giao duc
va hanh » van hanh, va thanh, va danh
hanh ki » hanh vi, hanh ky, hanh kien
x hoi » xa hoi, o hoi, x ho
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 ((sach ky) or (sach y)) nang x hoi. lieu va ((cao tuc) or (cao duc)) va hanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach y)) nang x hoi. lieu va ((cao tuc) OR (cao duc)) va hanh ki su triet.
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach y)) nang x hoi. lieu va ((cao tuc) or (cao duc)) va hanh ki su triet*.