Perhaps you should try some spelling variations:
nghien cac » nghiep cach, nghien cuu, nghiep cay
phan xuong » phan cong
phan cung » phan cong, phan ung, phan quang
mach hoc » cach hoc, dich hoc, anh hoc
cac cong » cua cong
cong hoa » dong hoa, dong hoc, hang hoa
nhan tao » nhan tai, nhan dan
tu mach » tu cach, tu manh, tu hach
va nhan » van nhan, ca nhan, va phan
ma hoi » mai hoi, xa hoi, ma hoa

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) OR (phan xuong)) hoc ma hoi va nhan tao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu mach hoc tap, nghien cac cong hoa ((phan cung) OR (phan xuong)) hoc ma hoi va nhan tao".
• Adding a wildcard symbol may retrieve word variants: tu mach hoc tap, nghien cac cong hoa ((phan cung) OR (phan xuong)) hoc ma hoi va nhan tao*.