Perhaps you should try some spelling variations:
hoc doanh » hoa doanh, hoc danh, hoc dan
doanh hoa » doanh khoa, doanh hoan, danh hoa
sach hoi » sach doi, sach moi, cach thoi
cuu dong » cuu cong, cuu tong, cuu long
dong hoc » dong co, dong luc
te sach » toc sach
va gian » va gianh, van gian, va gia
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: "te sach hoi dap, nghien cuu dong hoc doanh hoa hoc xa hoi ((va gian) OR (va giai)) lang~".
• Adding a wildcard symbol may retrieve word variants: te sach hoi dap, nghien cuu dong hoc doanh hoa hoc xa hoi ((va gian) OR (va giai)) lang*.