Perhaps you should try some spelling variations:
khoi doanh » hoa doanh, cho doanh, voi doanh
doanh khoa » toan khoa
tong khoi » xong khoi, tuong khoa, thong khoa
sach hoc » cach hoc, sach hoi, mach hoc
cuu tong » cuu cong, cuu tinh, huu tung
nhan van » nhan dan, nhan va, phan van
te sach » toc sach
va nhan » van nhan, ca nhan, va phan

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach hoc tap, nghien cuu tong khoi doanh khoa ((hoc xa) OR (hoc ma)) hoi va nhan van~".
• Adding a wildcard symbol may retrieve word variants: te sach hoc tap, nghien cuu tong khoi doanh khoa ((hoc xa) OR (hoc ma)) hoi va nhan van*.