Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
hanh lai » hanh lam, hanh tai, thanh lap
sach thu » sach thue, sach thieu, sach tham
van tham » van thanh, van tuan, van chat
thu nang » thi nang, thu hang, thu bang
duc ban » duc tan, duc van, duc man
dua ban » dia ban, cua ban, qua ban
lai cua » dai cua, hai cua, lai chau
su sach » so sach, vu 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: su sach thu nang ((x hoi) or (xa hoi)). hieu van tham ((duc ban) OR (dua ban)) hanh lai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu nang ((x hoi) OR (xa hoi)). hieu van tham ((duc ban) OR (dua ban)) hanh lai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thu nang ((x hoi) or (xa hoi)). hieu van tham ((duc ban) OR (dua ban)) hanh lai cua triet".
• Adding a wildcard symbol may retrieve word variants: su sach thu nang ((x hoi) or (xa hoi)). hieu van tham ((duc ban) OR (dua ban)) hanh lai cua triet*.