Perhaps you should try some spelling variations:
doanh khoa » toan khoa
coc doanh » cac doanh, hoa doanh, cho doanh
sach hoi » sach doi, sach moi, cach thoi
cuu cong » cua cong, thu cong, cac cong
cong coc » cong cuoc, cong cac, cong co
van nhan » van phan, van thanh, danh nhan
nhan van » nhan dan, nhan va, phan van
tu sach » thu sach, su sach, te sach
hoi van » hoi va, hoi dan, hai van

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 hoi dap, nghien cuu cong coc doanh khoa ((hoc xa) or (hoc ma)) hoi van nhan van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach hoi dap, nghien cuu cong coc doanh khoa ((hoc xa) OR (hoc ma)) hoi van nhan van.
• Adding a wildcard symbol may retrieve word variants: tu sach hoi dap, nghien cuu cong coc doanh khoa ((hoc xa) or (hoc ma)) hoi van nhan van*.