Perhaps you should try some spelling variations:
mai khoi » mai khoa, tai khoa, dai khoa
cac khoi » cac thoi, cac khoan, cach thoi
hieu van » hieu va, thien van, lieu va
nam duoc » nam thuoc, da duoc, dat duoc
va thanh » gia thanh, ban thanh, va tinh
duoc va » nuoc va, duc va, duoc ma
vai cua » dai cua, hai cua, lai cua
san ky » sang ky, van ky, dan ky
vi cua » di cua
phi » phai

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: phi san ky nang ((mai khoi) OR (cac khoi)). hieu van nam duoc va thanh ((vi cua) OR (vai cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "phi san ky nang ((mai khoi) OR (cac khoi)). hieu van nam duoc va thanh ((vi cua) or (vai cua)) tre~".
• Adding a wildcard symbol may retrieve word variants: phi san ky nang ((mai khoi) OR (cac khoi)). hieu van nam duoc va thanh ((vi cua) or (vai cua)) tre*.