Perhaps you should try some spelling variations:
so nganh » so ngan, hoc nganh, moi nganh
hanh hai » thanh hai, nhanh hai, hang hai
ky lang » ky dang, ky tang, tay lang
van hoi » van hoa, van hoc, van hoe
hieu ve » hieu va, hieu van
duc van » duc va, duc manh, duc phan
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
ve cao » va cao, ve bao, ve cac

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

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