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
hung thang » cang thang, hung tran
chua bang » chu bang, chua nang, thuat bang
chua xang » chua nang, chuc nang, chu bang
cua dang » cua cong, cua ban
toan cau » toan cao, toan ban, toan tap

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 - hung thang ((((chua bang) OR (chua xang))) or (cua dang)) phuong tinh toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo chieu sach - hung thang ((((chua bang) OR (chua xang))) OR (cua dang)) phuong tinh toan cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo chieu sach - hung thang ((((chua bang) OR (chua xang))) or (cua dang)) phuong tinh toan cau*".