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
mach hoc » cach hoc, dich hoc, anh hoc
cong hoc » dong hoc, cong hoa, cong coc
khoa hoc » hoa hoc
van nhan » van phan, van thanh, danh nhan
tu mach » tu cach, tu manh, tu hach
va nhan » ca nhan, va phan, va nha
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: tu mach hoc tap, nghien cua cong hoc doanh khoa hoc xa hoi ((va nhan) or (van nhan)) dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu mach hoc tap, nghien cua cong hoc doanh khoa hoc xa hoi ((va nhan) OR (van nhan)) dan.
• Adding a wildcard symbol may retrieve word variants: tu mach hoc tap, nghien cua cong hoc doanh khoa hoc xa hoi ((va nhan) or (van nhan)) dan*.