Perhaps you should try some spelling variations:
thuoc toan » thuoc thanh, thuat toan, thuoc tren
phau thong » phap thong, phan thong, phan thuong
khau thong » khau thuong, khap thong, khau tong
thuoc tan » thuoc tai, thuoc ban, thuoc tren
sach cay » sach cap, sach hay, sach nay
tu sach » thu sach, su sach, te sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach cay ((thuoc toan) OR (thuoc tan)) khoa ((phau thong) or (khau thong))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach cay ((thuoc toan) OR (thuoc tan)) khoa ((phau thong) OR (khau thong)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach cay ((thuoc toan) OR (thuoc tan)) khoa ((phau thong) or (khau thong))".
• Adding a wildcard symbol may retrieve word variants: tu sach cay ((thuoc toan) OR (thuoc tan)) khoa ((phau thong) or (khau thong))*.