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