Perhaps you should try some spelling variations:
doanh khoa » toan khoa
hoa doanh » toan doanh, hoa dan
thanh van » thanh san, thanh toan, thanh phan
sach hoc » cach hoc, sach hoi, mach hoc
cuu dong » cuu cong, cuu tong, cuu long
dong hoa » dong hoc, dong co
khoa hoc » hoa hoc
su sach » so sach, vu sach
hai van » thai van, ha van, hai tan
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: su sach hoc tap, nghien cuu dong hoa doanh khoa hoc xa ((hoi va) or (hai van)) thanh van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach hoc tap, nghien cuu dong hoa doanh khoa hoc xa ((hoi va) OR (hai van)) thanh van.
• Adding a wildcard symbol may retrieve word variants: su sach hoc tap, nghien cuu dong hoa doanh khoa hoc xa ((hoi va) or (hai van)) thanh van*.