Perhaps you should try some spelling variations:
nganh xay » nganh mac, nganh y, nganh ma
van hanh » van thanh, ban hanh, van anh
nganh ky » nganh y, hanh ky, nganh co
cau tren » cu tren, dau tren, ca tren
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
cau du » cau do, cac du, cau tu
vi cau » ve cau, di cau, viet cau
va cau » van cau, va cac, va dau

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) OR (nganh xay)) lang xa hoi. hieu va cau du ((van hanh) or (va danh)) vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((nganh ky) OR (nganh xay)) lang xa hoi. hieu va cau du ((van hanh) OR (va danh)) vi cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((nganh ky) OR (nganh xay)) lang xa hoi. hieu va cau du ((van hanh) or (va danh)) vi cau tren".
• Adding a wildcard symbol may retrieve word variants: so ((nganh ky) OR (nganh xay)) lang xa hoi. hieu va cau du ((van hanh) or (va danh)) vi cau tren*.