Perhaps you should try some spelling variations:
sanh trinh » hanh trinh, anh trinh, sinh trinh
trinh co » trinh do, trinh cong, trinh hoa
anh nhan » danh nhan, doanh nhan, thanh nhan
so sanh » do sanh
nhan ky » nhan y, nhat ky, than ky
so anh » so danh, do anh, ho anh
ky khi » ky thi, ly khi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( so sanh trinh co khi đong luc ) or ( so anh nhan ky khi đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( so sanh trinh co khi đong luc ) OR ( so anh nhan ky khi đong luc )).
• Adding a wildcard symbol may retrieve word variants: (( so sanh trinh co khi đong luc ) or ( so anh nhan ky khi đong luc ))*.