Perhaps you should try some spelling variations:
doanh khoa » toan khoa
cong chuc » cong thuc, cong cu, cong cua
sach hoc » cach hoc, sach hoi, mach hoc
cong cau » cong cu, thong cau, cong tac
khoa hoc » hoa hoc
dap nhan » dap nha, dac nhan, dam nhan
so sach » so sanh, bo sach, co sach
nhan va » nhan tai, nhan dan, nhan tao
hoc xa » hoc ma

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: "so sach hoc tap, nghien cuu ((cong cau) OR (cong chuc)) doanh khoa hoc xa hoi dap nhan va~".
• Adding a wildcard symbol may retrieve word variants: so sach hoc tap, nghien cuu ((cong cau) OR (cong chuc)) doanh khoa hoc xa hoi dap nhan va*.