Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
dua tren » dung tren
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
hieu ve » hieu va, hieu van
cua tre » cuu tre, cua triet, cua thep
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
ve cac » va cac, vien cac
du van » duy van, duc van, tu van
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky tang xa hoi. hieu ve cac du van hanh vi ((((cua tre) OR (dua tren))) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky tang xa hoi. hieu ve cac du van hanh vi ((((cua tre) OR (dua tren))) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky tang xa hoi. hieu ve cac du van hanh vi ((((cua tre) OR (dua tren))) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu sac ky tang xa hoi. hieu ve cac du van hanh vi ((((cua tre) OR (dua tren))) or (cua te))*.