Perhaps you should try some spelling variations:
chinh truong » chinh trong, sinh truong, trinh truong
hinh trong » chinh trong, dinh trong, sinh trong
hieu lang » chieu sang, hieu quang, nhieu tang
cong cong » cong dong, dung cong, dang cong
manh toan » thanh toan, anh tuan, tinh toan
hoc hieu » hoc thieu, hoc hien, doc hieu
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 hieu lang - ((chinh truong) or (hinh trong)) cua ((cong cong) OR (trong cong)) manh toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu lang - ((chinh truong) OR (hinh trong)) cua ((cong cong) OR (trong cong)) manh toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hieu lang - ((chinh truong) or (hinh trong)) cua ((cong cong) OR (trong cong)) manh toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - ((chinh truong) or (hinh trong)) cua ((cong cong) OR (trong cong)) manh toan cao*.