Perhaps you should try some spelling variations:
nghien cua » nghien cuu, nghiep cua, nghiep vua
doanh khoa » toan khoa
hoa doanh » toan doanh, hoa dan
sach hoc » cach hoc, sach hoi, mach hoc
cua dong » chua dong, cua cong, cua dang
dong hoa » dong hoc, dong co
nhan dan » phan dau, gian dan, nhan tai
te sach » toc sach
va nhan » van nhan, ca nhan, va phan

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 dong hoa doanh khoa ((hoc xa) or (hoc ma)) hoi va nhan dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach hoc tap, nghien cua dong hoa doanh khoa ((hoc xa) OR (hoc ma)) hoi va nhan dan.
• Adding a wildcard symbol may retrieve word variants: te sach hoc tap, nghien cua dong hoa doanh khoa ((hoc xa) or (hoc ma)) hoi va nhan dan*.