Perhaps you should try some spelling variations:
sanh nhan » danh nhan, anh nhan, hanh nhan
sach nhan » sach nha, sach han, sach ngan
nhan cong » nhanh cong, phan cong, nhap cong
cong khi » cong thai, khong khi, cong ha
vu sach » vu bach, su sach, vu khach
nhan co » nhan con, phan co, nhan mo
so sanh » do sanh

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