Perhaps you should try some spelling variations:
thanh trung » thanh tung
thieu sach » chieu sach, thien hach, hieu cach
hanh trinh » canh tranh, hanh chinh
nhung cong » dung cong, thong cong, hang cong
hoc thieu » toc thieu, hoc hien
khoan cam » khoa cam, khoan va, phan cam
cong san » cong tac
khan cap » khan ap, than cap, phan cac

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 - ((thanh trung) or (hanh trinh)) va nhung cong san ((khan cap) OR (khoan cam))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sach - ((thanh trung) OR (hanh trinh)) va nhung cong san ((khan cap) OR (khoan cam)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sach - ((thanh trung) or (hanh trinh)) va nhung cong san ((khan cap) OR (khoan cam))".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - ((thanh trung) or (hanh trinh)) va nhung cong san ((khan cap) OR (khoan cam))*.