Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh lai » hanh lam, hanh tai, thanh lap
van hanh » van thanh, ban hanh, van anh
lai cua » dai cua, hai cua, lai chau
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
ve bac » ve bao, ve ban, he bac
co hoi » co hoc, co loi
ve cac » va cac, vien cac
bo van » vo van, so van, do van
o hoi » o hoc, o hai, o hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang ((o hoi) or (co hoi)). hieu ((ve bac) OR (ve cac)) bo van hanh lai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((o hoi) OR (co hoi)). hieu ((ve bac) OR (ve cac)) bo van hanh lai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((o hoi) or (co hoi)). hieu ((ve bac) OR (ve cac)) bo van hanh lai cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((o hoi) or (co hoi)). hieu ((ve bac) OR (ve cac)) bo van hanh lai cua triet*.