Perhaps you should try some spelling variations:
mach hoc » cach hoc, dich hoc, anh hoc
hoc hang » hoc hanh, hoc bang, hoc tang
hang hoa » hang khoa, thanh hoa, hang va
nhan dan » phan dau, gian dan
nhan tai » hang tai, van tai, toan tai
so mach » so sach, tao mach, kon mach
cuu mon » cuu mo, cuu mot, cuu cong
mon hoc » toan hoc, dong hoc
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: so mach hoc tap, nghien cuu mon hoc hang hoa hoc xa hoi va ((nhan dan) or (nhan tai))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so mach hoc tap, nghien cuu mon hoc hang hoa hoc xa hoi va ((nhan dan) OR (nhan tai)).
• Adding a wildcard symbol may retrieve word variants: so mach hoc tap, nghien cuu mon hoc hang hoa hoc xa hoi va ((nhan dan) or (nhan tai))*.