Perhaps you should try some spelling variations:
sanh trinh » hanh trinh, anh trinh, sinh trinh
sach dang » sach dung, sach danh, sach nang
dang cong » dung cong
cong khi » cong thai, khong khi, cong ha
trinh co » trinh do, trinh cong, trinh hoa
su sach » so sach, vu sach
so sanh » do sanh

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

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