Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
toc sac » toc sach, toc san, hoc sach
sac ky » cac ky, sai ky
co loi » co hoi
ve dan » ke dan, va dan, he dan
le dan » ke dan
vat va » dat va
va dai » va dao, vi dai, va dau
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sac ky nang ((o hoi) or (co loi)). hieu ((ve dan) OR (le dan)) thuc vat va dai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sac ky nang ((o hoi) OR (co loi)). hieu ((ve dan) OR (le dan)) thuc vat va dai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sac ky nang ((o hoi) or (co loi)). hieu ((ve dan) OR (le dan)) thuc vat va dai cua triet".
• Adding a wildcard symbol may retrieve word variants: toc sac ky nang ((o hoi) or (co loi)). hieu ((ve dan) OR (le dan)) thuc vat va dai cua triet*.