Perhaps you should try some spelling variations:
nghien cac » nghiep cach, nghien cuu, nghiep cay
coc doanh » hoa doanh, cho doanh, voi doanh
cac doanh » cac dan, cac dang, van doanh
thu sach » tu sach, thuat sach, thuoc sach
sach doi » sach hoi, sach moi, sach dao
cac cong » cua cong
doi dap » hoi dap, doi dau, do dap
va pham » van pham, va phat, va phap
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: thu sach doi dap, nghien cac cong ((coc doanh) or (cac doanh)) hoa hoc xa hoi va pham van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach doi dap, nghien cac cong ((coc doanh) OR (cac doanh)) hoa hoc xa hoi va pham van.
• Adding a wildcard symbol may retrieve word variants: thu sach doi dap, nghien cac cong ((coc doanh) or (cac doanh)) hoa hoc xa hoi va pham van*.