Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
cham giua » tham gia, nhat giua, cam gia
qua cham » qua hai, qua cac, va cham
giua ban » giup ban, dia ban, cua ban
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ban anh » ban hanh, ban banh, ban danh
cua tre » cua te, cuu tre, dua tren
anh de » hanh de, anh d, anh ve
x hoi » o hoi, x ho, 5 hoi

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 ky nang ((x hoi) or (xa hoi)). hieu qua cham giua ban anh de ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (xa hoi)). hieu qua cham giua ban anh de ((cua tre) OR (cua triet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) or (xa hoi)). hieu qua cham giua ban anh de ((cua tre) or (cua triet))*.