Perhaps you should try some spelling variations:
dua tren » dung tren
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
va hanh » van hanh, va thanh, va danh
cuu tre » cua tre, cau tren, cau treo
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
ve cac » va cac, vien cac

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 lang xa hoi. hieu ve cac duc va hanh vi ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky lang xa hoi. hieu ve cac duc va hanh vi ((dua tren) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu sac ky lang xa hoi. hieu ve cac duc va hanh vi ((dua tren) or (cuu tre))*.