Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
nam truc » nam truoc, nam thuc, nam trung
van hanh » van thanh, ban hanh, van anh
cua tre » cua te, cuu tre, dua tren
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
nam tu » nam thu, nam thuc
x hoi » xa hoi, o hoi, x ho

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 x hoi. hieu van ((nam truc) or (nam tu)) van hanh vi ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang x hoi. hieu van ((nam truc) OR (nam tu)) van hanh vi ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang x hoi. hieu van ((nam truc) or (nam tu)) van hanh vi ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang x hoi. hieu van ((nam truc) or (nam tu)) van hanh vi ((cua tre) OR (cua triet))*.