Perhaps you should try some spelling variations:
khoa nganh » khoi nganh, hoc nganh
nganh nong » nganh cong
mach hoc » cach hoc, dich hoc, anh hoc
cuu toan » cuu hoan, cua toan, huu toan
vu mach » vi mach, vu bach, vu manh
thon xa » thong xa, thoi xa, thong xay
nhan va » nhan tai, nhan dan, nhan tao

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: vu mach hoc tap, nghien cuu toan khoa nganh nong thon xa hoi va ((nhan va) or (hang va))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu mach hoc tap, nghien cuu toan khoa nganh nong thon xa hoi va ((nhan va) OR (hang va)).
• Adding a wildcard symbol may retrieve word variants: vu mach hoc tap, nghien cuu toan khoa nganh nong thon xa hoi va ((nhan va) or (hang va))*.