Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
ky tang » ky nang, ky dang, kho tang
hieu va » lieu va, hieu qua
cuc tre » duc tre, cua tre, cuu tre
tu san » thu san, tu ban, tu can
san ky » sang ky, van ky, dan ky
ma hoi » mai hoi, ma hoa, me hoi
va lam » van lam, va lap
xuc va » tuc va, luc va, xac va

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 tang ((ma hoi) OR (xa hoi)). hieu va lam ((xuc va) OR (duc va)) thanh tai cuc tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu san ky tang ((ma hoi) OR (xa hoi)). hieu va lam ((xuc va) or (duc va)) thanh tai cuc tre~".
• Adding a wildcard symbol may retrieve word variants: tu san ky tang ((ma hoi) OR (xa hoi)). hieu va lam ((xuc va) or (duc va)) thanh tai cuc tre*.