Perhaps you should try some spelling variations:
phuong dinh » phuong binh, phuong linh, phuong trinh
chieu sach » chinh sach, chieu sang, chieu xanh
hanh hang » thanh hang, hang hang, hanh han
dinh toan » tinh toan, hinh toan, minh toan
cua bang » chua bang, cua ban, cua hang
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) OR (chiet tach)) - hanh hang ((cua bang) or (cua dang)) phuong dinh toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chieu sach) OR (chiet tach)) - hanh hang ((cua bang) OR (cua dang)) phuong dinh toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chieu sach) OR (chiet tach)) - hanh hang ((cua bang) or (cua dang)) phuong dinh toan cau".
• Adding a wildcard symbol may retrieve word variants: theo ((chieu sach) OR (chiet tach)) - hanh hang ((cua bang) or (cua dang)) phuong dinh toan cau*.