Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
thu sach » thuat sach, thuoc sach, thu hoach
hieu tuc » hieu thuc, hieu luc, hieu thuoc
va thanh » gia thanh, ban thanh, va tinh
phan lan » phan lap, phan van, phan loai
hang cao » hoang cao, nang cao, hang ca
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
hieu tu » chieu tu, hien tu, lieu tu
cao hoi » cau hoi, co hoi, cao hoc
ty hang » ly hang, ty xang, thi hang
tu sach » su sach, te sach, tu cach
lan va » luan va, lanh va, lan van

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) or (tu sach)) ty hang cao hoi. ((hieu tu) OR (hieu tuc)) phan lan va thanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (tu sach)) ty hang cao hoi. ((hieu tu) OR (hieu tuc)) phan lan va thanh tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (tu sach)) ty hang cao hoi. ((hieu tu) OR (hieu tuc)) phan lan va thanh tai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (tu sach)) ty hang cao hoi. ((hieu tu) OR (hieu tuc)) phan lan va thanh tai cua tre*.