Perhaps you should try some spelling variations:
quoc ban » quoc bao, quoc lan, quoc quan
ky lang » ky dang, ky tang, tay lang
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » lieu va, hieu qua
va chat » van chat, va phat, cao chat
xuc ban » duc ban, cuc ban, xuat ban
tu can » tu ban, tu cac, thu canh
vi cua » vai cua, di cua
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 can ((ky lang) or (ky nang)) 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 can ((ky lang) OR (ky nang)) 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 can ((ky lang) or (ky nang)) mai hoi. hieu va chat ((xuc ban) OR (quoc ban)) hanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: tu can ((ky lang) or (ky nang)) mai hoi. hieu va chat ((xuc ban) OR (quoc ban)) hanh vi cua te*.