Perhaps you should try some spelling variations:
doanh hoan » doanh doanh, doanh khoa, doanh nhan
doanh hoa » doanh khoa, danh hoa, doanh ha
gian lang » gian dan
thu sach » tu sach, thuat sach, thuoc sach
sach hoi » sach doi, sach moi, cach thoi
cuu dong » cuu cong, cuu tong, cuu long
dong hoc » dong co, dong luc
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: thu sach hoi dap, nghien cuu dong hoc ((doanh hoa) OR (doanh hoan)) hoc xa hoi va gian lang~.
• Adding a wildcard symbol may retrieve word variants: thu sach hoi dap, nghien cuu dong hoc ((doanh hoa) or (doanh hoan)) hoc xa hoi va gian lang*.