Perhaps you should try some spelling variations:
quang thien » quang tien, quang hien, quang dien
hanh doanh » hang doanh, chinh doanh, doanh doanh
chieu sach » chinh sach, chiet tach, chieu sang
dung thong » dung thuong, dong thong, dung thang
hieu sach » hieu cach, dien sach, hieu cac
doanh cua » doanh luan
thien van » thi 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 (chieu sach)) - hanh doanh cua ((dung thong) OR (dung trong)) quang thien van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sach) OR (chieu sach)) - hanh doanh cua ((dung thong) OR (dung trong)) quang thien van.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sach) or (chieu sach)) - hanh doanh cua ((dung thong) OR (dung trong)) quang thien van".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sach) or (chieu sach)) - hanh doanh cua ((dung thong) OR (dung trong)) quang thien van*.