Perhaps you should try some spelling variations:
chat triet » chet triet, phat trien, chat thien
thanh lam » thanh lap, hanh lam, thanh nam
ban thanh » ban hanh, ban hang
lam chat » luan chat, cao chat, ly chat
hieu van » hieu va, thien van, lieu va
duc ban » duc tan, duc van, dua ban
cau duc » cao duc, cau luc, chu duc
van cau » van dau, van hau, van chat
tu sach » thu sach, su sach, te sach
y nang » ky nang, ly nang, v nang
so hai » son hai, su hai, so ha
o hai » co hai, o lai, _ hai
o hoi » co hoi, o hoc, o hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y nang ((o hoi) or (((o hai) OR (so hai)))). hieu van cau duc ban thanh lam chat triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((o hoi) OR (((o hai) OR (so hai)))). hieu van cau duc ban thanh lam chat triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ((o hoi) or (((o hai) OR (so hai)))). hieu van cau duc ban thanh lam chat triet".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((o hoi) or (((o hai) OR (so hai)))). hieu van cau duc ban thanh lam chat triet*.