Perhaps you should try some spelling variations:
danh nhan » doanh nhan, thanh nhan, benh nhan
sach hoc » cach hoc, sach hoi, sach duoc
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 hoat » van hoa, dan hoc, danh hoa
hoat hoc » hoa hoc, hoat ho, khoa hoc
hoi danh » hop danh, hoi dan, hoc danh
nhan dan » phan dau, gian dan, nhan tai
hoc mai » hoc ma, hoc dai, hoc bai
mai hoi » mai khoi, dai hoi, lai hoi

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

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