Perhaps you should try some spelling variations:
nghien huu » nghien cuu, nguyen huu, nhiem huu
doanh khoa » toan khoa
cach thoi » cac thoi, cach thuc, cach noi
thu cach » thuc cach, thu canh, tu cach
thoi dap » hoi dap, thoi dai, thi dap
mot toan » mon toan, mot thanh, mot doanh
khoa hoc » hoa hoc
nhan dan » phan dau, gian dan, nhan tai
huu mot » cuu mot, huy mot, hieu mot
hai van » thai van, hai tan, hao van
hoc xa » hoc ma
ha van » hoa van, nha van, va van

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu cach thoi dap, nghien huu mot toan doanh khoa hoc xa ((hai van) or (ha van)) nhan dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu cach thoi dap, nghien huu mot toan doanh khoa hoc xa ((hai van) OR (ha van)) nhan dan.
• Adding a wildcard symbol may retrieve word variants: thu cach thoi dap, nghien huu mot toan doanh khoa hoc xa ((hai van) or (ha van)) nhan dan*.