Perhaps you should try some spelling variations:
va trien » va truyen, va thiet, va tuyen
cam luc » cam xuc, cau luc
va danh » va dinh, va dan, dia danh
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, ban hanh
sac ky » cac ky
va cam » va cham, va cac, va cao
de va » de van, te va, ke va

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sac ky) or (sai ky)) lang xa hoi. hieu va cam luc ((va hanh) OR (va danh)) de va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sac ky) OR (sai ky)) lang xa hoi. hieu va cam luc ((va hanh) OR (va danh)) de va trien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sac ky) or (sai ky)) lang xa hoi. hieu va cam luc ((va hanh) OR (va danh)) de va trien".
• Adding a wildcard symbol may retrieve word variants: te ((sac ky) or (sai ky)) lang xa hoi. hieu va cam luc ((va hanh) OR (va danh)) de va trien*.