Perhaps you should try some spelling variations:
tang dai » tang tai, tang dan, lang dai
danh dai » danh dau, danh di, danh sai
ky tang » ky nang, ky dang, kho tang
dai hoi » dai hoc, dai hai, dai moi
hieu ve » hieu va, hieu van
va danh » va dinh, va dan, va hanh
cua tre » cua te, cuu tre, cua triet
va sac » va cac, va suc, va san
sac ky » cac ky, sai ky
ve dat » de dat, va dat, ve dao

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: va sac ky tang dai hoi. hieu ve dat (nuoc or duoc) va danh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: va sac ky tang dai hoi. hieu ve dat (nuoc OR duoc) va danh dai cua tre*.