Perhaps you should try some spelling variations:
dang xay » dang van, van xay
tan hanh » tan thanh, tang hanh, toan hanh
cua viet » ca viet, hoa viet, cua vat
lang xa » lang ha, lang van
qua cac » cua cac
cac duc » cac du, cao duc, cac dac
hanh te » hanh tu, hanh ve, hanh de
tu can » tu ban, tu cac, thu canh
can ky » van ky, dan ky, ban ky
te cua » tue cua, le cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu can ky ((lang xa) or (dang xay)) hoi. hieu qua cac duc tan hanh te cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu can ky ((lang xa) OR (dang xay)) hoi. hieu qua cac duc tan hanh te cua viet.
• Adding a wildcard symbol may retrieve word variants: tu can ky ((lang xa) or (dang xay)) hoi. hieu qua cac duc tan hanh te cua viet*.