Perhaps you should try some spelling variations:
phan khong » phan hong, nhan khong, pham khong
khong hoc » khung hoc, thong hoc, khong thuoc
thanh hai » thanh phan, thanh hoa
hoc phan » hoc dan, hoc pho
anh hoc » sinh hoc, benh hoc, hinh hoc
cuu mot » cua mot, cuu mo, huu mot
mot hoc » mon hoc, mo hoc, mot goc
hoc mai » hoc ma, hoc dai, hoc bai
mai hoi » mai khoi, dai hoi, lai hoi
tu anh » tu hanh, tu manh, thu anh

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu anh hoc tap, nghien cuu mot hoc phan khong hoc mai hoi dap ((thanh hai) or (thanh san))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu anh hoc tap, nghien cuu mot hoc phan khong hoc mai hoi dap ((thanh hai) OR (thanh san)).
• Adding a wildcard symbol may retrieve word variants: tu anh hoc tap, nghien cuu mot hoc phan khong hoc mai hoi dap ((thanh hai) or (thanh san))*.