Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cac cuc » cac cuoc, cac nuoc, cac cach
cac cua » cach cua, cac qua, ca cua
hanh va » hang va, hanh vi
va cua » va chua, via cua, ca 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: tu sach ky nang ((x hoi) or (x ho)). hieu ve ((cac cuc) OR (cac cua)) ban hanh va cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (x ho)). hieu ve ((cac cuc) OR (cac cua)) ban hanh va cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) or (x ho)). hieu ve ((cac cuc) OR (cac cua)) ban hanh va cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) or (x ho)). hieu ve ((cac cuc) OR (cac cua)) ban hanh va cua triet*.