Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
va thanh » gia thanh, ban thanh, va tinh
mai khoi » mai khoa, tai khoa, cac khoi
tai cua » thai cua, tai cuc, tri cua
mai hoi » dai hoi, lai hoi, mai doi
nam hoc » nam moc, nam hoi, am hoc
va nam » van nam, ha nam, va nay
cua tu » cua tuc, cua su, cua cu
tay ky » tap ky
tan ky » than ky, tang ky, toan ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: thau ((tay ky) or (tan ky)) lang ((mai hoi) OR (mai khoi)). lieu va nam hoc va thanh tai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thau ((tay ky) OR (tan ky)) lang ((mai hoi) OR (mai khoi)). lieu va nam hoc va thanh tai cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thau ((tay ky) or (tan ky)) lang ((mai hoi) OR (mai khoi)). lieu va nam hoc va thanh tai cua tu".
• Adding a wildcard symbol may retrieve word variants: thau ((tay ky) or (tan ky)) lang ((mai hoi) OR (mai khoi)). lieu va nam hoc va thanh tai cua tu*.