Perhaps you should try some spelling variations:
quoc ban » quoc bao, quoc lan, quoc quan
lang mai » lang dai, lang hai, lang man
hieu va » lieu va, hieu qua
ky lang » ky nang, ky dang, ky tang
mai hoi » mai khoi, dai hoi, lai hoi
xuc ban » duc ban, cuc ban, xuat ban
va chat » van chat, va phat, cao chat
vi cua » vai cua, di cua
tu san » thu san, tu can, vu san
tu ban » thu ban, te ban
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu san) OR (tu ban)) ky lang mai hoi. hieu va chat ((xuc ban) or (quoc ban)) hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu san) OR (tu ban)) ky lang mai hoi. hieu va chat ((xuc ban) OR (quoc ban)) hanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu san) OR (tu ban)) ky lang mai hoi. hieu va chat ((xuc ban) or (quoc ban)) hanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: ((tu san) OR (tu ban)) ky lang mai hoi. hieu va chat ((xuc ban) or (quoc ban)) hanh vi cua te*.