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
van chat » cao chat
chat duc » chat xuc, chat doc, chet duoc
va thanh » gia thanh, ban thanh, va tinh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
lam cua » nam cua, lam chat
o hoi » co hoi, o hoc, o hoa
o hai » co hai, so hai, o lai

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 ky nang ((o hoi) or (o hai)). hieu van chat duc va thanh lam cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((o hoi) OR (o hai)). hieu van chat duc va thanh lam cua triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((o hoi) or (o hai)). hieu van chat duc va thanh lam cua triet*.