Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
doanh han » doanh nhan, doanh hoan, doanh phan
gian lang » gian dan
sach hoi » sach doi, sach moi, cach thoi
cuu dong » cuu cong, cuu tong, cuu long
dong hoc » dong co, dong luc
doanh ha » doanh va, doanh khoa, doanh nhan
va gian » va gianh, van gian, va giai
hoc xa » hoc ma

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

• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach hoi dap, nghien cuu dong hoc ((doanh ha) OR (doanh han)) hoc xa hoi va gian lang~.
• Adding a wildcard symbol may retrieve word variants: thuoc sach hoi dap, nghien cuu dong hoc ((doanh ha) or (doanh han)) hoc xa hoi va gian lang*.