Perhaps you should try some spelling variations:
doanh khoa » toan khoa
thanh van » thanh san, thanh toan, thanh phan
thu sach » tu sach, thuat sach, thuoc sach
sach hoc » cach hoc, sach hoi, mach hoc
cuu long » cuu cong, cuu tong, cuu nang
su doanh » so doanh, cua doanh, san doanh
khoa hoc » hoa hoc
thai van » thi van, thai vung, thai son
long su » luong su, dong su, long vu
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 hoc tap, nghien cuu long su doanh khoa hoc xa ((thai van) or (thai den)) thanh van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach hoc tap, nghien cuu long su doanh khoa hoc xa ((thai van) OR (thai den)) thanh van.
• Adding a wildcard symbol may retrieve word variants: thu sach hoc tap, nghien cuu long su doanh khoa hoc xa ((thai van) or (thai den)) thanh van*.