Perhaps you should try some spelling variations:
hanh hai » thanh hai, nhanh hai, hang hai
so hanh » so sanh, so danh, co hanh
hai cua » thai cua, dai cua, hoi cua
van hoi » van hoa, van hoc, van hoe
hieu ve » hieu va, hieu van
ky lang » ky dang, ky tang, tay lang
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
bac va » ban va, bac ha, tac va
bao va » bao ve, tao va, ban va

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

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