Perhaps you should try some spelling variations:
chat thien » phat trien, cai thien, phat hien
chat triet » chet triet, phat trien, cua triet
thanh lam » thanh lap, hanh lam, thanh nam
van thanh » ban thanh, van tuan
hieu van » hieu va, thien van, lieu va
duc van » duc va, duc tan, duc manh
van cau » van dau, van hau, van chat
cau duc » cao duc, cau luc, chu duc
sac ky » cac ky, sai ky
tu sac » tu sach, tu cac, tu san
o hai » co hai, so hai, o lai
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 sac ky nang ((o hoi) or (o hai)). hieu van cau duc van thanh lam ((chat triet) OR (chat thien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang ((o hoi) OR (o hai)). hieu van cau duc van thanh lam ((chat triet) OR (chat thien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang ((o hoi) or (o hai)). hieu van cau duc van thanh lam ((chat triet) OR (chat thien))".
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang ((o hoi) or (o hai)). hieu van cau duc van thanh lam ((chat triet) OR (chat thien))*.