Perhaps you should try some spelling variations:
ban hanh » ban hang
cham duc » pham duc, cham soc, pham duy
dang xay » van xay
dang van » hoang van, hang va
hanh ve » hanh vi, hanh va, hanh kem
duc ban » duc tan, duc van, dua ban
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
dang ky » dang y, dong ky, duong ky
su viet » so viet
dan ky » van ky
ve su » va su

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((dang ky) or (dan ky)) ((dang xay) or (dang van)) hoi. hieu ve cham duc ban hanh ve su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((dang ky) OR (dan ky)) ((dang xay) OR (dang van)) hoi. hieu ve cham duc ban hanh ve su viet.
• Adding a wildcard symbol may retrieve word variants: tu ((dang ky) or (dan ky)) ((dang xay) or (dang van)) hoi. hieu ve cham duc ban hanh ve su viet*.