Perhaps you should try some spelling variations:
hanh trung » thanh trung, hanh trang, manh trung
nhung cong » dung cong, thong cong, hang cong
hien hach » thien hach, hien hanh, hien nhanh
trung cua » truong cua, trung tuan, trung cap
dang cong » dung cong
dang thai » dang thi, dang hai, dang khai
dan thai » dan thi, dan than, ban thai

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien hach - hanh trung cua ((nhung cong) OR (dang cong)) ((dan thai) OR (dang thai)) cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hien hach - hanh trung cua ((nhung cong) or (dang cong)) ((dan thai) OR (dang thai)) cao~".
• Adding a wildcard symbol may retrieve word variants: hoc hien hach - hanh trung cua ((nhung cong) or (dang cong)) ((dan thai) OR (dang thai)) cao*.