Perhaps you should try some spelling variations:
nghien huu » nghien cuu, nguyen huu, nhiem huu
khoa nganh » khoi nganh, hoc nganh
nganh nong » nganh cong
mach hoc » cach hoc, dich hoc, anh hoc
huu toan » huu tuan, cuu toan, huy toan
nong hoc » dong hoc, nang hoc, nong thon
toan tai » toan tap, doanh tai, toan ban
tu mach » tu cach, tu manh, tu hach
van tai » von tai, van tuan
hoc xa » hoc ma
xa hoc » xa hoi, va hoc, xa 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 huu toan khoa nganh nong hoc xa hoc dan ((toan tai) or (van tai))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu mach hoc tap, nghien huu toan khoa nganh nong hoc xa hoc dan ((toan tai) OR (van tai)).
• Adding a wildcard symbol may retrieve word variants: tu mach hoc tap, nghien huu toan khoa nganh nong hoc xa hoc dan ((toan tai) or (van tai))*.