Perhaps you should try some spelling variations:
khoan khau » khoanh khac, khoa kham, khoa phau
khau thong » khau thuong, khap thong, khau tong
sach tai » sach bai, sach tham, sach dao
so sach » bo sach, co sach, hoc sach
so sanh » do sanh
tue cac » tu cac, tuc cac, te cac
tu sach » thu sach, su sach, te sach
khoa he » hoa he, khoa hoc, khong he
tai le » thi le, tri le, tai he
le da » le dan, le dac, le dai

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( ((so sach) OR (so sanh)) tri tue cac khoan khau thong ) or ( tu sach tai le da khoa he thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((so sach) OR (so sanh)) tri tue cac khoan khau thong ) OR ( tu sach tai le da khoa he thong )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((so sach) OR (so sanh)) tri tue cac khoan khau thong ) or ( tu sach tai le da khoa he thong ))".
• Adding a wildcard symbol may retrieve word variants: (( ((so sach) OR (so sanh)) tri tue cac khoan khau thong ) or ( tu sach tai le da khoa he thong ))*.