Perhaps you should try some spelling variations:
hoc nganh » hoc nhanh
hanh hai » thanh hai, nhanh hai, hang hai
van hanh » van thanh, ban hanh, van anh
hai cua » thai cua, dai cua, hoi cua
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
van hoi » van hoa, van hoc, van hoe
ky dang » ky nang, ky danh
ky tang » ky nang, kho tang, ky trong
va cao » va cac, va co, va dao
ve cao » ve bao, ve cac, ve co

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

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