Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
cua tre » cua te, cuu tre, cua triet
van hac » van hoc, van ha, van hai
tai cua » thai cua, tai cuc, tri cua
va hanh » van hanh, va thanh, va danh
truc va » thuc va, thuc vat, trung va
van cac » van cau, van bac, dan cac
cao hoc » co hoc, cho hoc, chat hoc
cao hoi » cau hoi, co hoi, tao hoi
sac ky » cac ky, sai ky
su sac » su sach, su cac, su xac

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 sac ky nang ((cao hoi) OR (cao hoc)). hieu ((van cac) OR (van hac)) truc va hanh tai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky nang ((cao hoi) OR (cao hoc)). hieu ((van cac) or (van hac)) truc va hanh tai cua tre~".
• Adding a wildcard symbol may retrieve word variants: su sac ky nang ((cao hoi) OR (cao hoc)). hieu ((van cac) or (van hac)) truc va hanh tai cua tre*.