Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van tham » van thanh, van tuan, van chat
tham duc » pham duc, tham du, than duc
hanh lai » hanh lam, hanh tai, thanh lap
cao hoi » co hoi, cao hoc, tao hoi
va hanh » van hanh, va thanh, va danh
lai cua » dai cua, hai cua, lai chau
cua tre » cua te, cuu tre, cua triet
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky nang ((cao hoi) or (cau hoi)). hieu van tham duc va hanh lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky nang ((cao hoi) OR (cau hoi)). hieu van tham duc va hanh lai cua tre.
• Adding a wildcard symbol may retrieve word variants: te sac ky nang ((cao hoi) or (cau hoi)). hieu van tham duc va hanh lai cua tre*.