Perhaps you should try some spelling variations:
thanh ca » thanh cha, thanh cac, thanh ha
va thanh » gia thanh, ban thanh, va tinh
cua tre » cua te, cuu tre, cua triet
cac lop » cac hop, cac loai
hieu ve » hieu va, hieu van
van hoe » van hoa, van hoc, van hieu
van hoi » van hoa, van hoc, van loi
ky lang » ky nang, ky dang, ky tang
ve cac » va cac, vien cac
lop va » lap va, hop va, nop va
va sac » va cac, va suc, va san
ca cua » co cua
vu sac » vu sach, vu san, vu cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sac) OR (va sac)) ky lang ((van hoi) or (van hoe)). hieu ve cac lop va thanh ca cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sac) OR (va sac)) ky lang ((van hoi) OR (van hoe)). hieu ve cac lop va thanh ca cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sac) OR (va sac)) ky lang ((van hoi) or (van hoe)). hieu ve cac lop va thanh ca cua tre*".