Perhaps you should try some spelling variations:
nghien cua » nghien cuu, nghiep cua, nghiep vua
mach hoc » cach hoc, dich hoc, anh hoc
cong hoa » dong hoa, dong hoc, hang hoa
dan khoa » dang khoa, da khoa, san khoa
khoa hoc » hoa hoc
cac phan » cac nhan, cao phan, cap phan
tu mach » tu cach, tu manh, tu hach
ca phan » cao phan, cap phan, cau phan
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 hoa dan khoa hoc xa hoi ((ca phan) or (cac phan)) van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu mach hoc tap, nghien cua cong hoa dan khoa hoc xa hoi ((ca phan) OR (cac phan)) van.
• Adding a wildcard symbol may retrieve word variants: tu mach hoc tap, nghien cua cong hoa dan khoa hoc xa hoi ((ca phan) or (cac phan)) van*.