Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
doi chieu » doc hieu, ho chieu, mot chieu
trinh vat » trinh van, trinh luat, sinh vat
dung cong » dung trong
tong cong » trong cong, cong cong, dang cong
manh toan » thanh toan, anh tuan, tinh toan
toan cau » toan cao, toan ban, toan tap
doi chi » doi khi

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doi chieu) or (doi chi)) sach - canh trinh vat ((dung cong) or (tong cong)) manh toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (doi chi)) sach - canh trinh vat ((dung cong) OR (tong cong)) manh toan cau.
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) or (doi chi)) sach - canh trinh vat ((dung cong) or (tong cong)) manh toan cau*.