Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu nang » thi nang, thu hang, thu bang
hieu van » hieu va, thien van, lieu va
van tuan » van quan, van ban, anh tuan
tuan duc » tran duc, xuan duc, than duc
ban hanh » ban hang
hanh hai » thanh hai, nhanh hai, hang hai
va triet » va thiet, va trien, ve triet
su sach » so sach, vu sach
duc ban » duc tan, duc van, dua ban
hai va » hai van, thai va, hoi va
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 tuan duc ban hanh hai va 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 tuan duc ban hanh hai va triet.
• Adding a wildcard symbol may retrieve word variants: su sach thu nang ((x hoi) or (xa hoi)). hieu van tuan duc ban hanh hai va triet*.