Perhaps you should try some spelling variations:
thuoc sach » hoc sach, thuat sach, thuoc sinh
trung thuc » trong thuc, trang thuc, thuong thuc
truc thuoc » thuc thuc, tri thuoc, tu thuoc
nuoc sach » nguoi sach, hoc sach, cuoc cach
khoa khoa » hoa khoa, khuan khoa, khoa hoc
khoa khi » khoa kham, khong khi, khoa khac

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thuoc sach) or (nuoc sach)) ((trung thuc) or (truc thuoc)) bach ((khoa khi) OR (khoa khoa)) tuong~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thuoc sach) OR (nuoc sach)) ((trung thuc) OR (truc thuoc)) bach ((khoa khi) OR (khoa khoa)) tuong.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thuoc sach) or (nuoc sach)) ((trung thuc) or (truc thuoc)) bach ((khoa khi) OR (khoa khoa)) tuong".
• Adding a wildcard symbol may retrieve word variants: ((thuoc sach) or (nuoc sach)) ((trung thuc) or (truc thuoc)) bach ((khoa khi) OR (khoa khoa)) tuong*.