Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
trinh tuan » trinh quan, trinh toan, trinh luan
tuan thong » toan thong, tran thong, tuan phong
thong cong » trong cong, tong cong, thong thong
hieu sach » chieu sach, hieu cach, hieu cac
dien sach » dien anh
cong tan » cong tac, cong san, cong thanh
tran van » luan van

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu sach) or (dien sach)) - hanh trinh tuan thong cong tan tran van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sach) OR (dien sach)) - hanh trinh tuan thong cong tan tran van*.