Perhaps you should try some spelling variations:
chieu tinh » trieu tinh, lieu tinh, chau tinh
phuong dan » phuong danh, phuong doan, phuong lan
doi chieu » doc hieu, doi chi, ho chieu
hanh hanh » hanh han, xanh hanh, nhanh thanh
va thong » va thuong, va phuong, he thong
toan cao » toan tap
toan ban » van ban
hanh va » hang va, hanh vi

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: doi chieu tinh - hanh hanh va thong ((phuong dan) OR (huong dan)) ((toan cao) OR (toan ban))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi chieu tinh - hanh hanh va thong ((phuong dan) OR (huong dan)) ((toan cao) or (toan ban))~".
• Adding a wildcard symbol may retrieve word variants: doi chieu tinh - hanh hanh va thong ((phuong dan) OR (huong dan)) ((toan cao) or (toan ban))*.