Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
hanh trinh » canh tranh
thiet bang » thien bang, khien bang, nhiet nang
hoc thien » hoc hien, hoc thieu, hoc thiet
bang cong » dang cong, bang song, hang cong
cong van » cong vang, cong san, song van
van hang » van khang, van hoang, van thang
hang cac » hang ca, hang cau, bang cac

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 hach - ((hanh trinh) or (hanh chinh)) thiet bang cong van hang cac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thien hach - ((hanh trinh) OR (hanh chinh)) thiet bang cong van hang cac.
• Adding a wildcard symbol may retrieve word variants: hoc thien hach - ((hanh trinh) or (hanh chinh)) thiet bang cong van hang cac*.