Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hieu van » hieu va, thien van, lieu va
hanh lai » hanh lam, hanh tai, thanh lap
ban hanh » ban hang
tham duc » pham duc, tham du, than duc
van tham » van thanh, van tuan, van chat
thi nang » thi cong, ki nang, thi hanh
duc ban » duc tan, duc van, dua ban
so sanh » do sanh
lai cua » dai cua, hai cua, lai chau
so sach » bo sach, co sach, hoc sach
x hoi » o hoi, x ho, 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: ((so sach) OR (so sanh)) thi nang ((x hoi) or (xa hoi)). hieu van tham duc ban hanh lai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (so sanh)) thi nang ((x hoi) OR (xa hoi)). hieu van tham duc ban hanh lai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) OR (so sanh)) thi nang ((x hoi) or (xa hoi)). hieu van tham duc ban hanh lai cua viet".
• Adding a wildcard symbol may retrieve word variants: ((so sach) OR (so sanh)) thi nang ((x hoi) or (xa hoi)). hieu van tham duc ban hanh lai cua viet*.