Perhaps you should try some spelling variations:
khong thuoc » khang thuoc, hong phuoc, dong thuoc
nganh khong » nganh cong, nhanh chong, nganh nong
nghien cac » nghiep cach, nghien cuu, nghiep cay
hoc nganh » hoc nhanh
kon mach » ke mach, ban mach
mach hoc » cach hoc, dich hoc, anh hoc
cac cong » cua cong
cong hoc » dong hoc, cong hoa, cong coc
thuoc va » thuc va, thuoc ma, thuong va
nhan tai » hang tai, van tai, toan tai
va hoi » xa hoi, va hoc, va hoa
hoi ca » hoi cua, hoi cac, hoi cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: kon mach hoc tap, nghien cac cong hoc nganh khong thuoc va hoi ca ((nhan tai) or (dung tai))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: kon mach hoc tap, nghien cac cong hoc nganh khong thuoc va hoi ca ((nhan tai) OR (dung tai)).
• Adding a wildcard symbol may retrieve word variants: kon mach hoc tap, nghien cac cong hoc nganh khong thuoc va hoi ca ((nhan tai) or (dung tai))*.