Perhaps you should try some spelling variations:
sach nhah » sach nha, cach nhanh, sach tham
sach nhan » sach nha, sach han, sach ngan
cong khi » cong thai, khong khi, cong hai
vu sach » vu bach, vu khach
nhan co » nhan con, phan co, nhan mo
su sach » so sach
cong ha » cong hoa, dong ha, cong tac

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: (( vu sach nhan co khi đong luc ) OR ( su sach nhah ((cong khi) OR (cong ha)) đong luc ))~.
• Adding a wildcard symbol may retrieve word variants: (( vu sach nhan co khi đong luc ) or ( su sach nhah ((cong khi) or (cong ha)) đong luc ))*.