Perhaps you should try some spelling variations:
phuong cong » phuong dong, phong cong, phung cong
theo chieu » theo tieu, theo chu, thi chieu
hanh hang » thanh hang, hanh han, hanh mang
hang hang » nang hang, cang thang, hung thang
va phuong » va thuong, cac phuong
ho chieu » hoc thieu, doi chieu, mot chieu
cong san » cong tac
san toan » van toan, dan toan, 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: ((theo chieu) or (ho chieu)) sach - ((hanh hang) OR (hang hang)) va phuong cong san toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((theo chieu) OR (ho chieu)) sach - ((hanh hang) OR (hang hang)) va phuong cong san toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((theo chieu) or (ho chieu)) sach - ((hanh hang) OR (hang hang)) va phuong cong san toan cau".
• Adding a wildcard symbol may retrieve word variants: ((theo chieu) or (ho chieu)) sach - ((hanh hang) OR (hang hang)) va phuong cong san toan cau*.