Perhaps you should try some spelling variations:
nghien cua » nghien cuu, nghiep cua, nghiep vua
cach hoi » cach thoi, cach noi, cach hoc
cong hoc » dong hoc, cong hoa, cong coc
dan khoa » dang khoa, da khoa, san khoa
khoa hoc » hoa hoc
tu cach » tu cac
van tai » von tai, van tuan

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 hoi dap, nghien cua cong hoc dan khoa hoc ((xa hoi) or (ma hoa)) va van tai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cach hoi dap, nghien cua cong hoc dan khoa hoc ((xa hoi) OR (ma hoa)) va van tai.
• Adding a wildcard symbol may retrieve word variants: tu cach hoi dap, nghien cua cong hoc dan khoa hoc ((xa hoi) or (ma hoa)) va van tai*.