Perhaps you should try some spelling variations:
ban thanh » ban hang
vien cac » vien bach, vien dai, vien da
ban hanh » ban hang
thu sac » thu sach, thu san, thu xac
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
ve cac » va cac
va cua » va chua, via cua, ca cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thu sac ky lang xa hoi. hieu ((ve cac) or (vien cac)) lo ((ban thanh) OR (ban hanh)) va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sac ky lang xa hoi. hieu ((ve cac) OR (vien cac)) lo ((ban thanh) OR (ban hanh)) va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sac ky lang xa hoi. hieu ((ve cac) or (vien cac)) lo ((ban thanh) OR (ban hanh)) va cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sac ky lang xa hoi. hieu ((ve cac) or (vien cac)) lo ((ban thanh) OR (ban hanh)) va cua tre*.