Perhaps you should try some spelling variations:
thuong cong » thuong con, thuong dong, truong cong
theo chieu » ho chieu, theo chu, thi chieu
hanh trinh » canh tranh, hanh chinh
thong cong » trong cong, tong cong, thong thong
trinh cua » tinh cua, trinh luat, trinh quan
bai toan » bai tap
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 (theo tieu)) sach - hanh trinh cua ((thuong cong) or (thong cong)) bai toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((theo chieu) OR (theo tieu)) sach - hanh trinh cua ((thuong cong) OR (thong cong)) bai toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((theo chieu) OR (theo tieu)) sach - hanh trinh cua ((thuong cong) or (thong cong)) bai toan cau".
• Adding a wildcard symbol may retrieve word variants: ((theo chieu) OR (theo tieu)) sach - hanh trinh cua ((thuong cong) or (thong cong)) bai toan cau*.