Perhaps you should try some spelling variations:
trinh chuan » trinh han, trinh quan, trinh luan
theo chieu » theo tieu, ho chieu, theo chu
chieu sach » chinh sach, chiet tach, chieu sang
trinh chua » trinh cua, trinh chu, tinh chua
hang cong » dang cong, hang nong, bang cong
van thanh » ban thanh, van tuan
dan chan » dan gian, dan ca, van chat

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

• If you are trying to use Boolean operators, they must be ALL CAPS: theo chieu sach - hanh ((trinh chua) OR (trinh chuan)) hang cong ((dan chan) OR (van thanh)) cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo chieu sach - hanh ((trinh chua) OR (trinh chuan)) hang cong ((dan chan) or (van thanh)) cau~".
• Adding a wildcard symbol may retrieve word variants: theo chieu sach - hanh ((trinh chua) OR (trinh chuan)) hang cong ((dan chan) or (van thanh)) cau*.