Perhaps you should try some spelling variations:
nghien thu » nghiem thuc, nghiep thuc, nghien cuu
dong thanh » truong thanh
thai dong » thai cong, thai long, thai muong
thanh van » thanh san, thanh toan, thanh phan
thu mach » thu sach, thuat mach, thu hoach
mach hoc » cach hoc, dich hoc, anh hoc
so doanh » su doanh, hoa doanh, cho doanh
khoa hoc » hoa hoc
so danh » do danh, so sanh, so dan
ma thai » mai thai, mau thai, ca thai

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

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