Perhaps you should try some spelling variations:
ban thanh » ban hanh
qua tham » qua cham, qua than, qua thanh
ban hang » ngan hang
ky tang » ky dang, kho tang, ky trong
hoa hoi » khoa hoi, hoa hoc, hoa doi
tham so » ham so, tham do, than so
cua tre » cua te, cuu tre, cua triet
te cao » te bao
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: te cao ((ky tang) OR (ky nang)) hoa hoi. hieu qua tham so ((ban thanh) or (ban hang)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te cao ((ky tang) OR (ky nang)) hoa hoi. hieu qua tham so ((ban thanh) OR (ban hang)) vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te cao ((ky tang) OR (ky nang)) hoa hoi. hieu qua tham so ((ban thanh) or (ban hang)) vi cua tre*".