Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
ban hanh » ban hang
danh ky » hanh ky, dang ky, nganh ky
mai hoi » mai khoi, dai hoi, lai hoi
qua cac » cua cac
cac tac » cac toc, cac bac, cac dac
tac ban » tai ban, cac ban, tao ban
doi cua » hoi cua
dan ky » van ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: so ((danh ky) OR (dan ky)) nang mai hoi. hieu qua cac tac ban hanh ((doi cua) or (dai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((danh ky) OR (dan ky)) nang mai hoi. hieu qua cac tac ban hanh ((doi cua) OR (dai cua)) triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((danh ky) OR (dan ky)) nang mai hoi. hieu qua cac tac ban hanh ((doi cua) or (dai cua)) triet*".