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

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) OR (thu 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) OR (thu 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) OR (thu sach)) cay ((thuoc toan) or (thuoc tan)) khoa ((phau thong) or (khau thong))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) cay ((thuoc toan) or (thuoc tan)) khoa ((phau thong) or (khau thong))*.