Perhaps you should try some spelling variations:
hanh trang » thanh trung, hanh trinh, minh trang
nhung cong » dung cong, thong cong, hang cong
hoc thieu » toc thieu, hoc hien
ho chieu » theo chieu, doi chieu, mot chieu
cong bai » cuong bai, cong hai, cung bai
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: ((ho chieu) OR (hoc thieu)) sach - ((hanh trang) or (canh tranh)) va nhung cong bai toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (hoc thieu)) sach - ((hanh trang) OR (canh tranh)) va nhung cong bai toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) OR (hoc thieu)) sach - ((hanh trang) or (canh tranh)) va nhung cong bai toan cau".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) OR (hoc thieu)) sach - ((hanh trang) or (canh tranh)) va nhung cong bai toan cau*.