Perhaps you should try some spelling variations:
thuoc mach » thuoc sach, thuong mach, thuoc ma
nghien thu » nghiem thuc, nghiep thuc, nghien cuu
ban thanh » ban hang
mach hoc » cach hoc, dich hoc, anh hoc
khoa hoc » hoa hoc
ban hanh » ban hang
cong so » cong san, cong hoa
so toan » so tan, so than, bao toan
hoc xa » hoc ma
xa hai » xa thai, xua hai, xa hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc mach hoc tap, nghien thu cong so toan khoa hoc xa hai ((ban thanh) or (ban hanh)) van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc mach hoc tap, nghien thu cong so toan khoa hoc xa hai ((ban thanh) OR (ban hanh)) van.
• Adding a wildcard symbol may retrieve word variants: thuoc mach hoc tap, nghien thu cong so toan khoa hoc xa hai ((ban thanh) or (ban hanh)) van*.