Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh vai » hanh vi, hanh va, hanh tai
duc manh » suc manh, duc anh, duc minh
vai cua » dai cua, hai cua, lai cua
duc van » duc va, duc tan, duc phan
su sach » so sach, vu sach
va cham » va chat, va tham
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
o hoc » co hoc, mo hoc, so hoc
o hoi » co hoi, o hai, o hoa

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

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