Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
thong cong » trong cong, thong thong, phong chong
doi chieu » doc hieu, doi chi, mot chieu
tong cong » trong cong, cong cong, dung cong
ho chieu » theo chieu, hoc thieu, mot chieu
trinh ve » trinh he, trinh va, trinh vi
dan toan » van toan, dan than, manh toan
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: ((ho chieu) or (doi chieu)) sach - hanh trinh ve ((thong cong) OR (tong cong)) dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (doi chieu)) sach - hanh trinh ve ((thong cong) OR (tong cong)) dan toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) or (doi chieu)) sach - hanh trinh ve ((thong cong) OR (tong cong)) dan toan cao".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (doi chieu)) sach - hanh trinh ve ((thong cong) OR (tong cong)) dan toan cao*.