Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
hanh trinh » canh tranh, hanh chinh
trinh luan » trinh luat, trinh quan, trinh han
chong cong » cong cong, cuong cong, phong cong
thong cong » trong cong, tong cong, thong thong
hoc thieu » toc thieu, hoc hien
quan cau » quang cao, toan cau, quan ha
tuan cu » tuan tu, quan cua, tuan thu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thieu sach - hanh trinh luan ((chong cong) OR (thong cong)) van ((quan cau) or (tuan cu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sach - hanh trinh luan ((chong cong) OR (thong cong)) van ((quan cau) OR (tuan cu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sach - hanh trinh luan ((chong cong) OR (thong cong)) van ((quan cau) or (tuan cu))".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - hanh trinh luan ((chong cong) OR (thong cong)) van ((quan cau) or (tuan cu))*.