Perhaps you should try some spelling variations:
hoc doanh » hoa doanh, hoc danh, hoc dan
sach doi » sach hoi, sach moi, sach dao
te sach » toc sach
doi dap » hoi dap, doi dau, do dap
cuu mot » cua mot, cuu mo, huu mot
mot hoc » mon hoc, mo hoc, mot goc
ca luan » cu luan, ca lua, ca quan
hoi ca » hoi cua, hoi cac, hoi cau

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 doi dap, nghien cuu mot hoc doanh ((khoa hoc) or (hoa hoc)) xa hoi ca luan van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach doi dap, nghien cuu mot hoc doanh ((khoa hoc) OR (hoa hoc)) xa hoi ca luan van.
• Adding a wildcard symbol may retrieve word variants: te sach doi dap, nghien cuu mot hoc doanh ((khoa hoc) or (hoa hoc)) xa hoi ca luan van*.