Perhaps you should try some spelling variations:
mach hoc » cach hoc, dich hoc, anh hoc
cuu tong » cuu cong, cuu tinh, huu tung
khoa hoc » hoa hoc
nhan dan » phan dau, gian dan, nhan tai
su mach » su sach
va nhan » van nhan, ca nhan, va phan
hoc da » hoc dai, hoc dat, hoc dao
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 da) OR (hoc dan)) khoa hoc ma hoi va nhan dan~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su mach hoc tap, nghien cuu tong ((hoc da) OR (hoc dan)) khoa hoc ma hoi va nhan dan".
• Adding a wildcard symbol may retrieve word variants: su mach hoc tap, nghien cuu tong ((hoc da) OR (hoc dan)) khoa hoc ma hoi va nhan dan*.