Perhaps you should try some spelling variations:
nghien cac » nghiep cach, nghien cuu, nghiep cay
mach hoc » cach hoc, dich hoc, anh hoc
cac cong » cua cong
cong hoa » dong hoa, dong hoc, hang hoa
hoa phan » hoa dan, co phan
cung hoc » chung hoc, dung hoc, ung hoc
vung hoc » dung hoc, vung moc, trung hoc
nhan tao » nhan tai, nhan dan
tu mach » tu cach, tu manh, tu hach
mai hoi » mai khoi, dai hoi, lai hoi
va nhan » van nhan, ca nhan, va phan

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