Perhaps you should try some spelling variations:
thanh phong » thanh phuong, khanh phong, thanh hong
thiet tach » chiet tach, thien hach, thuat tach
cach chung » cac chung, cac chuong, cach dung
hoc thiet » hoc thieu, hoc thuyet, hoc hien
cong phan » cong nhan, cong khan, chong phap
phan toan » phan tan, phap toan, pham toan
cach ung » cach dung, cac ung, cach mang
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: hoc thiet tach - thanh phong ((cach ung) or (cach chung)) cong phan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet tach - thanh phong ((cach ung) OR (cach chung)) cong phan toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc thiet tach - thanh phong ((cach ung) or (cach chung)) cong phan toan cau*.