Perhaps you should try some spelling variations:
tang mai » tang ma, tang tai, lang mai
ban hanh » ban hang
ve chao » ve chat, ve cham, ve chang
mai hoi » mai khoi, dai hoi, lai hoi
vi cua » vai cua, di cua
xu ban » xuc ban, tu ban, vu ban
ve cho » ve co, ve che, de cho
san ky » sang ky, dan ky, ban ky
cua te » cua tu

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((san ky) OR (van ky)) tang mai hoi. hieu ((ve chao) OR (ve cho)) xu ban hanh vi cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((san ky) OR (van ky)) tang mai hoi. hieu ((ve chao) or (ve cho)) xu ban hanh vi cua te~".
• Adding a wildcard symbol may retrieve word variants: tu ((san ky) OR (van ky)) tang mai hoi. hieu ((ve chao) or (ve cho)) xu ban hanh vi cua te*.