Perhaps you should try some spelling variations:
sanh hoc » sinh hoc, anh hoc, danh hoc
hoc phan » hoc dan, hoc pho
phan hoa » phan loai, phan phoi, phan hong
tap doan » tap quan
so sanh » do sanh
va toan » van toan, bai toan, tap toan
mo hoc » mon hoc, co 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 sanh hoc tap, nghien cuu mo hoc phan hoa hoc xa hoi ((va toan) or (tap doan)) tai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sanh hoc tap, nghien cuu mo hoc phan hoa hoc xa hoi ((va toan) OR (tap doan)) tai.
• Adding a wildcard symbol may retrieve word variants: so sanh hoc tap, nghien cuu mo hoc phan hoa hoc xa hoi ((va toan) or (tap doan)) tai*.