Perhaps you should try some spelling variations:
mach hoc » cach hoc, dich hoc, anh hoc
cuu tong » cuu cong, cuu tinh, huu tung
tong hoc » tuong hoc, thong hoc, trong hoc
dan khoa » dang khoa, da khoa, san khoa
khoa hoc » hoa hoc
nhan dan » phan dau, nhan tai
gian dan » gian lang
su mach » su sach
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: su mach hoc tap, nghien cuu tong hoc dan khoa hoc ma hoi va ((nhan dan) or (gian dan))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su mach hoc tap, nghien cuu tong hoc dan khoa hoc ma hoi va ((nhan dan) OR (gian dan)).
• Adding a wildcard symbol may retrieve word variants: su mach hoc tap, nghien cuu tong hoc dan khoa hoc ma hoi va ((nhan dan) or (gian dan))*.