Perhaps you should try some spelling variations:
hieu sach » chieu sach, hieu cach, dien sach
tran tuan » tran thanh, tranh luan, tran van
tran xuan » tran van
dung cong » dung trong
doc hieu » toc thieu, hoc thieu, hoc hien
cong san » cong tac
san toan » van toan, dan toan, manh toan
toan tap » toan ban

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 - thanh ((((tran tuan) OR (tran xuan))) or (tran quang)) dung cong san toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sach - thanh ((((tran tuan) OR (tran xuan))) OR (tran quang)) dung cong san toan tap*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu sach - thanh ((((tran tuan) OR (tran xuan))) or (tran quang)) dung cong san toan tap*".