Perhaps you should try some spelling variations:
thien chanh » thien thanh, thien chinh, tien thanh
hanh trinh » canh tranh, hanh chinh
hien hanh » dieu hanh
trinh he » trinh han, trinh hoa, trinh thi
van toan » van tan, van thanh, manh toan
van tuan » van quan, van ban, anh tuan
he dung » he dong, te dung, nghe dung

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thien chanh) or (hien hanh)) - hanh trinh he dung trong ((van toan) OR (van tuan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thien chanh) OR (hien hanh)) - hanh trinh he dung trong ((van toan) OR (van tuan)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thien chanh) or (hien hanh)) - hanh trinh he dung trong ((van toan) OR (van tuan)) cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((thien chanh) or (hien hanh)) - hanh trinh he dung trong ((van toan) OR (van tuan)) cao*.