Perhaps you should try some spelling variations:
thuc ban » thuoc ban, thu ban, thuc van
nang mai » nang ma, nang tai, lang mai
thuc dan » thuc hanh, hoc dan, thuc vat
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
ve tham » va tham, ve cham, vi tham
va chua » vua chua, ca chua, va chu
tu cao » cu cao, tu cac, vu cao
va cua » via cua, ca cua, ma cua

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 cao ky nang mai hoi. hieu ve tham ((thuc ban) OR (thuc dan)) thanh ((va cua) OR (va chua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cao ky nang mai hoi. hieu ve tham ((thuc ban) OR (thuc dan)) thanh ((va cua) or (va chua)) tre~".
• Adding a wildcard symbol may retrieve word variants: tu cao ky nang mai hoi. hieu ve tham ((thuc ban) OR (thuc dan)) thanh ((va cua) or (va chua)) tre*.