Perhaps you should try some spelling variations:
doanh thong » doanh thuong, doanh tong, doanh trong
nghien thu » nghiem thuc, nghiep thuc, nghien cuu
hoa doanh » toan doanh, hoa dan
thong hoc » thuong hoc, tuong hoc, thong hoa
sach hoc » cach hoc, sach hoi, mach hoc
cong hoa » dong hoa, dong hoc, hang hoa
nhan dan » phan dau, gian dan, nhan tai
tu sach » thu sach, su sach, te sach
nhan va » nhan tai, nhan tao, phan van
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: tu sach hoc tap, nghien thu cong hoa doanh thong hoc xa hoi va ((nhan va) or (nhan dan))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach hoc tap, nghien thu cong hoa doanh thong hoc xa hoi va ((nhan va) OR (nhan dan)).
• Adding a wildcard symbol may retrieve word variants: tu sach hoc tap, nghien thu cong hoa doanh thong hoc xa hoi va ((nhan va) or (nhan dan))*.