Perhaps you should try some spelling variations:
danh nhan » thanh nhan, benh nhan, dung nhan
cac thoi » cac toi, cac hop, cac tro
thoi tap » toi tap, hoc tap, thoi dai
hop toan » hop hoan, phap toan, tap toan
khoa hoc » hoa hoc
vu cac » va cac, tu cac, ve cac
mo hop » mo hoc, mo ho, so hop
hoc xa » hoc ma

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu cac thoi tap, nghien cuu mo hop toan khoa hoc xa hoi ((danh nhan) or (doanh nhan)) van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu cac thoi tap, nghien cuu mo hop toan khoa hoc xa hoi ((danh nhan) OR (doanh nhan)) van.
• Adding a wildcard symbol may retrieve word variants: vu cac thoi tap, nghien cuu mo hop toan khoa hoc xa hoi ((danh nhan) or (doanh nhan)) van*.