Perhaps you should try some spelling variations:
thiet thanh » thien thanh, thi thanh, viet thanh
thanh dung » thanh duong, thanh tung, thanh hung
cua thuong » cua truong, cua phuong, ca thuong
hoc thiet » hoc thieu, hoc thuyet, hoc hien
dung cua » dung luan, dung cho
cong tan » cong tac, cong thanh, cong ty
cong san » cong tac
phan cau » phan dau, phan tu, phan lap
phan cac » nhan cach, phan dau, phan lap

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 thanh - thanh dung cua thuong ((cong tan) or (cong san)) ((phan cau) or (phan cac))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet thanh - thanh dung cua thuong ((cong tan) OR (cong san)) ((phan cau) OR (phan cac)).
• Adding a wildcard symbol may retrieve word variants: hoc thiet thanh - thanh dung cua thuong ((cong tan) or (cong san)) ((phan cau) or (phan cac))*.