Perhaps you should try some spelling variations:
nghien cac » nghiep cach, nghien cuu, nghiep cay
phan cung » phan cong, phan ung, phan xuong
van thanh » ban thanh, van tuan
thanh tao » thanh thao, thanh tai, thanh tay
mach hoc » cach hoc, dich hoc, anh hoc
cac cong » cua cong
cong coc » cong cuoc, cong cac, cong co
coc phan » co phan, hoc phan, cac phan
cung hoc » chung hoc, dung hoc, vung hoc
tu mach » tu cach, tu manh, tu hach
ma hoi » mai hoi, xa hoi, me hoi

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 cac cong coc phan cung hoc ((ma hoi) or (ma hoa)) van thanh tao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu mach hoc tap, nghien cac cong coc phan cung hoc ((ma hoi) OR (ma hoa)) van thanh tao.
• Adding a wildcard symbol may retrieve word variants: tu mach hoc tap, nghien cac cong coc phan cung hoc ((ma hoi) or (ma hoa)) van thanh tao*.