Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
nhung cong » dung cong, thong cong, hang cong
doi chieu » doi chi, ho chieu, mot chieu
trinh cua » tinh cua, trinh luat, trinh quan
bang cong » dang cong, bang song, hang cong
doc hieu » toc thieu, hoc thieu, hoc hien
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap

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 (doc hieu)) sach - hanh trinh cua ((nhung cong) or (bang cong)) dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (doc hieu)) sach - hanh trinh cua ((nhung cong) OR (bang cong)) dan toan cau.
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) or (doc hieu)) sach - hanh trinh cua ((nhung cong) or (bang cong)) dan toan cau*.