Perhaps you should try some spelling variations:
doanh khoa » toan khoa
ban thanh » ban hanh, ban hang
thanh van » thanh san, thanh toan, thanh phan
hinh hoc » sinh hoc, tin hoc, benh hoc
khoa hoc » hoa hoc
anh hoc » sinh hoc, benh hoc, anh khoa
mo toan » mon toan, so toan, bao toan
doi ban » di ban, do ban, dong ban
ma doi » mai doi, va doi, ma di

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

• Performing a fuzzy search may retrieve terms with similar spellings: ke ((anh hoc) or (hinh hoc)) tap, nghien cuu mo toan doanh khoa hoc ma doi ban thanh van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ke ((anh hoc) OR (hinh hoc)) tap, nghien cuu mo toan doanh khoa hoc ma doi ban thanh van.
• Adding a wildcard symbol may retrieve word variants: ke ((anh hoc) or (hinh hoc)) tap, nghien cuu mo toan doanh khoa hoc ma doi ban thanh van*.