Perhaps you should try some spelling variations:
thien chanh » thien thanh, thien chinh, hien hanh
dung thuong » hang thuong, cong thuong, dung thuoc
thien dang » thien bang, thien danh, thien nang
thanh tinh » thanh binh, nhanh tinh, than kinh
tinh cua » trinh cua, sinh cua, tinh chat
van phan » van phong, van thanh, luan phan
phan lap » phan dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thien chanh) or (thien dang)) - thanh tinh cua ((dung thuong) OR (dung trong)) van phan lap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thien chanh) OR (thien dang)) - thanh tinh cua ((dung thuong) OR (dung trong)) van phan lap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thien chanh) or (thien dang)) - thanh tinh cua ((dung thuong) OR (dung trong)) van phan lap".
• Adding a wildcard symbol may retrieve word variants: hoc ((thien chanh) or (thien dang)) - thanh tinh cua ((dung thuong) OR (dung trong)) van phan lap*.