Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
ban thanh » ban hanh, ban hang
van tham » van thanh, van tuan, van chat
nang mai » nang ma, nang tai, lang mai
thuc ban » thuoc ban, thuc dan, thu ban
hieu van » hieu va, thien van, lieu va
mai hoi » mai khoi, dai hoi, lai hoi
vu cao » cu cao, va cao
va cua » va chua, via cua, ca cua
va chu » va che, va cau, va chi
tu cao » cu cao, tu cac, su cao

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