Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
van hanh » van thanh, ban hanh, van anh
hanh dai » hanh tai, hanh dao, vanh dai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ve bac » ve bao, ve cac, he bac
ve ban » te ban, va ban, ve bao
bo van » vo van, so van, do van
x hoi » o hoi, x ho, 5 hoi

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 ((x hoi) OR (xa hoi)). hieu ((ve bac) OR (ve ban)) bo van hanh dai cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) OR (xa hoi)). hieu ((ve bac) OR (ve ban)) bo van hanh dai cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) OR (xa hoi)). hieu ((ve bac) OR (ve ban)) bo van hanh dai cua triet*.