Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
van hanh » van thanh, ban hanh, van anh
hanh va » hang va, hanh vi
hieu ve » hieu va, hieu van
tu cach » tu cac
su sach » so sach, vu sach
ve ban » te ban, va ban, ve bao
ban bo » can bo, ban do, ban co
bo van » vo van, so van, do van
o hoc » co hoc, mo hoc, so hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cach) or (su sach)) ky nang ((o hoc) or (xa hoi)). hieu ve ban bo van hanh va su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (su sach)) ky nang ((o hoc) OR (xa hoi)). hieu ve ban bo van hanh va su triet.
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (su sach)) ky nang ((o hoc) or (xa hoi)). hieu ve ban bo van hanh va su triet*.