Perhaps you should try some spelling variations:
vien cac » vien bach, vien dai, vien da
va tinh » may tinh
tang xa » trang xa, tang ma, lang xa
hieu va » lieu va, hieu qua
cam luc » cam xuc, cau luc
ve cac » va cac
luc va » duc va, tuc va, loc va
ban ky » van ky
dan ky » van ky
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((ban ky) OR (dan ky)) tang xa hoi. hieu va cam luc va tinh ((ve cac) or (vien cac)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((ban ky) OR (dan ky)) tang xa hoi. hieu va cam luc va tinh ((ve cac) OR (vien cac)) tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((ban ky) OR (dan ky)) tang xa hoi. hieu va cam luc va tinh ((ve cac) or (vien cac)) tren".
• Adding a wildcard symbol may retrieve word variants: tu ((ban ky) OR (dan ky)) tang xa hoi. hieu va cam luc va tinh ((ve cac) or (vien cac)) tren*.