Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
te sach » toc sach
tai cua » thai cua, tai cuc, tri cua
tai cuu » tai cuc, tai buu, thai cua
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
lai hoi » dai hoi, lai hoa, lai roi
mai hoi » mai khoi, dai hoi, mai doi
ve cac » va cac, vien cac
cac tu » cac thu, cach tu, cac du

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky nang ((mai hoi) OR (lai hoi)). hieu ve cac tu va thanh ((tai cuu) or (tai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ((mai hoi) OR (lai hoi)). hieu ve cac tu va thanh ((tai cuu) OR (tai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ((mai hoi) OR (lai hoi)). hieu ve cac tu va thanh ((tai cuu) or (tai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((mai hoi) OR (lai hoi)). hieu ve cac tu va thanh ((tai cuu) or (tai cua)) tre*.