Perhaps you should try some spelling variations:
sanh ngoai » san ngoai, doanh ngoai, ban ngoai
ngoai cong » ngoai trong, nguoi cong, noi cong
sach ngon » sach ngan, danh ngon, canh ngon
ngon cong » neon cong, nganh cong, nguoi cong
cong khi » cong thai, khong khi, co khi
so sanh » do sanh
vu sach » vu bach, su sach, vu khach

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