Perhaps you should try some spelling variations:
quan trong » gian trong
hieu manh » chieu xanh, hieu nganh, dieu hanh
hanh tang » hanh trang, anh tang, hanh mang
tang quan » tang luan, nang quan, tong quan
hach toan » thanh toan, manh toan
hoc hieu » hoc thieu, hoc hien, doc hieu
tam toan » tap toan, tam than, pham toan

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hieu manh - hanh tang quan trong cong ((hach toan) or (tam toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu manh - hanh tang quan trong cong ((hach toan) OR (tam toan)) cau*.