Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
trinh cong » trinh dung
sach ninh » sach kinh, bac ninh, sach danh
cong khi » cong thai, khong khi, cong ha
su sach » so sach, vu sach
ninh co » kinh co, tinh co, dinh co
su canh » suc canh, su can, su anh

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 ninh co khi đong luc ) or ( su canh trinh cong khi đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su sach ninh co khi đong luc ) OR ( su canh trinh cong khi đong luc )).
• Adding a wildcard symbol may retrieve word variants: (( su sach ninh co khi đong luc ) or ( su canh trinh cong khi đong luc ))*.