Perhaps you should try some spelling variations:
sang mai » sang ma, sang tai, lang mai
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
mai hoi » mai khoi, dai hoi, lai hoi
sach ty » sach y, sach tu, sach thu
van cai » van chi, van cau, van ai
van hai » van ha, van chat, van hanh
sac ky » cac ky, sai ky
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ty) or (sac ky)) sang mai hoi. hieu ((van cai) OR (van hai)) dat va thanh vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ty) OR (sac ky)) sang mai hoi. hieu ((van cai) OR (van hai)) dat va thanh vi cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ty) or (sac ky)) sang mai hoi. hieu ((van cai) OR (van hai)) dat va thanh vi cua vat".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ty) or (sac ky)) sang mai hoi. hieu ((van cai) OR (van hai)) dat va thanh vi cua vat*.