Perhaps you should try some spelling variations:
nghien cau » nghien cuu, nghiep cau, nghiep cay
nganh khoa » nganh hoa, nganh khong, doanh khoa
cach thuc » anh thuc, cac thu
hoc nganh » hoc nhanh
mach hoc » cach hoc, dich hoc, anh hoc
khoa hoc » hoa hoc
cua toan » cuu toan, xuan toan, cua thanh
toan tai » toan tap, doanh tai, toan ban
hoi hoc » hoa hoc, hoi chuc
hoi cua » hoi chuc
hoc xa » hoc ma

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) or (cach thuc)) tap, nghien cau hoi hoc nganh khoa hoc xa hoi cua toan tai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((mach hoc) OR (cach thuc)) tap, nghien cau hoi hoc nganh khoa hoc xa hoi cua toan tai.
• Adding a wildcard symbol may retrieve word variants: tu ((mach hoc) or (cach thuc)) tap, nghien cau hoi hoc nganh khoa hoc xa hoi cua toan tai*.