Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
sach ky » sac ky, sach y, sach ty
cau bao » ca bao, cu bao, cuu bao
cua tre » cua te, cuu tre, dua tren
nang o » nang co, nang ho, nang ro
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: te sach ky nang o hai. hieu van ((cau bao) OR (cau tao)) van hanh vi ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang o hai. hieu van ((cau bao) OR (cau tao)) van hanh vi ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang o hai. hieu van ((cau bao) OR (cau tao)) van hanh vi ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang o hai. hieu van ((cau bao) OR (cau tao)) van hanh vi ((cua tre) or (cua triet))*.