Perhaps you should try some spelling variations:
doanh khoa » toan khoa
hoc doanh » hoa doanh, hoc danh, hoc dan
mach hoc » cach hoc, dich hoc, anh hoc
cuu tong » cuu cong, cuu tinh, huu tung
tong hoc » tuong hoc, thong hoc, trong hoc
khoa hoc » hoa hoc
tu mach » tu cach, tu manh, tu hach
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 tap, nghien cuu tong hoc doanh khoa hoc xa hoi va ((gian lang) or (gian dan))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu mach hoc tap, nghien cuu tong hoc doanh khoa hoc xa hoi va ((gian lang) OR (gian dan)).
• Adding a wildcard symbol may retrieve word variants: tu mach hoc tap, nghien cuu tong hoc doanh khoa hoc xa hoi va ((gian lang) or (gian dan))*.