Perhaps you should try some spelling variations:
doanh trong » doanh tong, doanh thuong, dinh trong
sach tham » sach nha
tan doanh » toan doanh, van doanh, san doanh
tham tai » pham tai, thai tai, thap tai
cuu cong » cua cong, thu cong, cac cong
cong tan » cong tac, cong san, cong thanh
tai toan » bai toan, tap toan, tai tuan
toan tai » toan tap, doanh tai, toan ban
su sach » so sach, vu sach
hoi tai » hoc tai, hoi trac

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 tham tai, nghien cuu cong tan doanh trong ((hoc xa) or (hoc ma)) hoi tai toan tai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tham tai, nghien cuu cong tan doanh trong ((hoc xa) OR (hoc ma)) hoi tai toan tai.
• Adding a wildcard symbol may retrieve word variants: su sach tham tai, nghien cuu cong tan doanh trong ((hoc xa) or (hoc ma)) hoi tai toan tai*.