Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thanh lam » thanh lap, hanh lam, thanh nam
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, ban thanh, va tinh
lam cua » nam cua, lam chat
cao duc » dao duc, cao suc, giao duc
cau duc » cau luc, chu duc, cau truc
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
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: su sach ky nang ((o hoi) or (o hai)). hieu van ((cau duc) OR (cao duc)) va thanh lam cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((o hoi) OR (o hai)). hieu van ((cau duc) OR (cao duc)) va thanh lam cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ((o hoi) or (o hai)). hieu van ((cau duc) OR (cao duc)) va thanh lam cua triet".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((o hoi) or (o hai)). hieu van ((cau duc) OR (cao duc)) va thanh lam cua triet*.