Perhaps you should try some spelling variations:
khong thuoc » khang thuoc, hong phuoc, dong thuoc
ngan khong » nganh khong, nhan khong, ngan hang
dong luat » dong luan, dung luat, dong luc
luat ngan » cua ngan, luat dan
cuu dong » cuu cong, cuu tong, cuu long
thuoc va » thuc va, thuoc ma, thuong va
tu sach » thu sach, su sach, te sach
so sach » so sanh, bo sach, co sach
va nhan » van nhan, ca nhan, va phan
nhan va » nhan tai, nhan dan, nhan tao
va hoi » xa hoi, va hoc, va hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (so sach)) hoi dap, nghien cuu dong luat ngan khong thuoc va hoi va nhan va~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (so sach)) hoi dap, nghien cuu dong luat ngan khong thuoc va hoi va nhan va.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (so sach)) hoi dap, nghien cuu dong luat ngan khong thuoc va hoi va nhan va*.