Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
cac toc » cac toi, cac nuoc, cac thoi
cac tac » cac bac, cac dac, cac tai
dan thi » dang thi, tran thi, dinh thi
cua tre » cua te, cuu tre, dua tren
y nang » ky nang, ly nang, v nang
va dan » ca dan, va dao, va dau

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 y nang xa hoi. hieu qua ((cac toc) or (cac tac)) va dan thi ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang xa hoi. hieu qua ((cac toc) OR (cac tac)) va dan thi ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang xa hoi. hieu qua ((cac toc) or (cac tac)) va dan thi ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang xa hoi. hieu qua ((cac toc) or (cac tac)) va dan thi ((cua tre) OR (cua triet))*.