Perhaps you should try some spelling variations:
nghien cua » nghien cuu, nghiep cua, nghiep vua
doanh khoa » toan khoa
hoc doanh » hoa doanh, hoc danh, hoc dan
thoi dai » hoc dai, hoi dan
cong hoc » dong hoc, cong hoa, cong coc
khoa hoc » hoa hoc
tu cach » tu cac
van tai » von tai, van tuan
hoa vo » hoa co

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cach ((thoi dai) or (hoi dap)), nghien cua cong hoc doanh khoa hoc ma hoa vo van tai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cach ((thoi dai) OR (hoi dap)), nghien cua cong hoc doanh khoa hoc ma hoa vo van tai.
• Adding a wildcard symbol may retrieve word variants: tu cach ((thoi dai) or (hoi dap)), nghien cua cong hoc doanh khoa hoc ma hoa vo van tai*.