Perhaps you should try some spelling variations:
hoa doanh » toan doanh, hoa dan
doanh hoa » doanh khoa, doanh hoan, danh hoa
sach hoc » cach hoc, sach hoi, mach hoc
cuu dong » cuu cong, cuu tong, cuu long
dong hoa » dong hoc, dong co
nhan dan » phan dau, nhan tai
gian dan » gian lang
su sach » so sach, vu sach
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: su sach hoc tap, nghien cuu dong hoa doanh hoa hoc xa hoi va ((nhan dan) or (gian dan))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach hoc tap, nghien cuu dong hoa doanh hoa hoc xa hoi va ((nhan dan) OR (gian dan)).
• Adding a wildcard symbol may retrieve word variants: su sach hoc tap, nghien cuu dong hoa doanh hoa hoc xa hoi va ((nhan dan) or (gian dan))*.