Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
qua cham » qua hai, qua cac, va cham
tu sach » thu sach, su sach, te sach
duc ban » duc tan, duc van, duc man
dua ban » dia ban, cua ban, qua ban
cua tre » cua te, cuu tre, dua tren
y nang » ky nang, ly nang, v nang
anh do » anh doc, anh d, anh co
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 sach y nang x hoi. hieu qua cham ((duc ban) or (dua ban)) anh do ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang x hoi. hieu qua cham ((duc ban) OR (dua ban)) anh do ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang x hoi. hieu qua cham ((duc ban) or (dua ban)) anh do ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang x hoi. hieu qua cham ((duc ban) or (dua ban)) anh do ((cua tre) OR (cua triet))*.