Perhaps you should try some spelling variations:
nang van » dang van, tang van, lang van
duc manh » suc manh, duc anh, duc minh
hanh hai » thanh hai, nhanh hai, hang hai
cua viet » ca viet, cua vat, cua dieu
so sanh » do sanh
sanh ky » hanh ky, sang ky, nganh ky
van hoi » van hoa, van hoc, van hoe
hieu va » lieu va, hieu qua
duc van » duc va, duc tan, duc phan

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

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