Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thu sach » tu sach, thuat sach, thuoc sach
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
va nam » ha nam, va nay
thu va » thuc va, thue va, tu va
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, 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: thu sach ky nang ((x hoi) or (x ho)). hieu ((va nam) OR (van nam)) thu va hanh vi cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((x hoi) OR (x ho)). hieu ((va nam) OR (van nam)) thu va hanh vi cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ((x hoi) or (x ho)). hieu ((va nam) OR (van nam)) thu va hanh vi cua triet".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ((x hoi) or (x ho)). hieu ((va nam) OR (van nam)) thu va hanh vi cua triet*.