Perhaps you should try some spelling variations:
trinh thiet » trinh viet, trinh thi
thien hach » thien thanh, hien hanh
hanh trinh » canh tranh, hanh chinh
hien sach » dien sach, kien sach, chieu sach
hang nong » thang long, han tong
dang cong » dung cong
van hang » van khang, van hoang, van thang
hang cac » hang ca, hang cau, bang 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 ((hien sach) or (thien hach)) - hanh trinh thiet ((hang nong) or (dang cong)) van hang cac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien sach) OR (thien hach)) - hanh trinh thiet ((hang nong) OR (dang cong)) van hang cac.
• Adding a wildcard symbol may retrieve word variants: hoc ((hien sach) or (thien hach)) - hanh trinh thiet ((hang nong) or (dang cong)) van hang cac*.