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
nhan dan » phan dau, gian dan, nhan tai
su mach » su sach
va nhan » van nhan, ca nhan, va phan
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) OR (hoa 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 dan ((khoa hoc) OR (hoa hoc)) ma hoi va nhan dan".
• Adding a wildcard symbol may retrieve word variants: su mach hoc tap, nghien cuu tong hoc dan ((khoa hoc) OR (hoa hoc)) ma hoi va nhan dan*.