Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
duc manh » suc manh, duc anh, duc minh
hanh dai » hanh tai, hanh dao, vanh dai
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
duc van » duc va, duc tan, duc phan
ve cam » ve cham, va cam, ve cai
ve cac » va cac, vien cac
x hoi » xa hoi, o hoi, x ho

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 ty nang x hoi. hieu ((ve cam) OR (ve cac)) ((duc van) or (duc manh)) hanh dai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang x hoi. hieu ((ve cam) OR (ve cac)) ((duc van) OR (duc manh)) hanh dai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang x hoi. hieu ((ve cam) OR (ve cac)) ((duc van) or (duc manh)) hanh dai cua triet".
• Adding a wildcard symbol may retrieve word variants: su sach ty nang x hoi. hieu ((ve cam) OR (ve cac)) ((duc van) or (duc manh)) hanh dai cua triet*.