Perhaps you should try some spelling variations:
dung thuong » dung trong, hang thuong, cong thuong
canh trinh » canh tranh, hanh trinh, canh tinh
dung huong » dung phuong, dong huong, dung luong
doi chieu » doc hieu, doi chi, mot chieu
trinh van » trinh han, trinh quan, trinh toan
ho chieu » theo chieu, hoc thieu, mot chieu
dan phan » doan phan, dan chan, van phan

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 (doi chieu)) sach - canh trinh van ((dung huong) or (dung thuong)) dan phan tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (doi chieu)) sach - canh trinh van ((dung huong) OR (dung thuong)) dan phan tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) OR (doi chieu)) sach - canh trinh van ((dung huong) or (dung thuong)) dan phan tu".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) OR (doi chieu)) sach - canh trinh van ((dung huong) or (dung thuong)) dan phan tu*.