Perhaps you should try some spelling variations:
quoc lan » quoc ban, nuoc luan, quoc quan
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
cuu tre » cau tren, cau treo
cua tre » cua te, cua triet, dua tren
xuc ban » duc ban, cuc ban, quoc ban
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, ma hoa
tu sac » tu sach, tu cac, tu san

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 sac ky tang ma hoi. hieu van cham ((xuc ban) OR (quoc lan)) hanh vi ((cua tre) OR (cuu tre))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky tang ma hoi. hieu van cham ((xuc ban) or (quoc lan)) hanh vi ((cua tre) OR (cuu tre))~".
• Adding a wildcard symbol may retrieve word variants: tu sac ky tang ma hoi. hieu van cham ((xuc ban) or (quoc lan)) hanh vi ((cua tre) OR (cuu tre))*.