Perhaps you should try some spelling variations:
nghien cua » nghien cuu, nghiep cua, nghiep vua
sach hoc » cach hoc, sach hoi, mach hoc
dan nhan » danh nhan, dan chan, van nhan
te sach » toc sach
cua van » cua ban, cua vat, cua dan
van hoc » van hoa
dan hoa » danh hoa, dan hoat, dan khoa
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: te sach hoc tap, nghien cua van hoc dan hoa hoc xa hoi ((dan nhan) or (doanh nhan)) tao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach hoc tap, nghien cua van hoc dan hoa hoc xa hoi ((dan nhan) OR (doanh nhan)) tao.
• Adding a wildcard symbol may retrieve word variants: te sach hoc tap, nghien cua van hoc dan hoa hoc xa hoi ((dan nhan) or (doanh nhan)) tao*.