Perhaps you should try some spelling variations:
sach kem » hanh kem
ban hang » ngan hang
cham cua » chat cua, cham cuu, ham cua
dang xay » dang van, van xay
qua cham » qua hai, qua cac, va cham
ban dan » ban hanh, ban quan, gian dan
xay hoi » xa hoi, tay hoi, cay phoi
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
vi cua » vai cua, di cua

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 kem) or (sac ky)) dang xay hoi. hieu qua cham cua ((ban dan) OR (ban hang)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach kem) OR (sac ky)) dang xay hoi. hieu qua cham cua ((ban dan) OR (ban hang)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach kem) or (sac ky)) dang xay hoi. hieu qua cham cua ((ban dan) OR (ban hang)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach kem) or (sac ky)) dang xay hoi. hieu qua cham cua ((ban dan) OR (ban hang)) vi cua tre*.