Perhaps you should try some spelling variations:
hanh trinh » hanh chinh
nhung cong » dung cong, thong cong, hang cong
cua nhung » va nhung
cong van » cong vang, cong san, song van
oi viet » hoi viet, cuoi viet, gioi viet
van tai » von tai, van tuan
tai tap » bai tap, tai tao, hai tap
o viet » so viet, hoc viet

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((oi viet) OR (o viet)) tach - ((hanh trinh) or (canh tranh)) cua nhung cong van tai tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((oi viet) OR (o viet)) tach - ((hanh trinh) OR (canh tranh)) cua nhung cong van tai tap*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((oi viet) OR (o viet)) tach - ((hanh trinh) or (canh tranh)) cua nhung cong van tai tap*".