Perhaps you should try some spelling variations:
phuong tinh » phuong trinh, phuong binh, khuong tinh
theo chieu » theo tieu, ho chieu, theo chu
chieu sach » chinh sach, chiet tach, chieu sang
hanh trung » thanh trung, hanh trang, manh trung
toan cau » toan cao, toan ban, toan tai
toan tap » toan ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo chieu sach - hanh trung ((cua chu) OR (sua chua)) phuong tinh ((toan cau) or (toan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo chieu sach - hanh trung ((cua chu) OR (sua chua)) phuong tinh ((toan cau) OR (toan tap)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo chieu sach - hanh trung ((cua chu) OR (sua chua)) phuong tinh ((toan cau) or (toan tap))".
• Adding a wildcard symbol may retrieve word variants: theo chieu sach - hanh trung ((cua chu) OR (sua chua)) phuong tinh ((toan cau) or (toan tap))*.