Perhaps you should try some spelling variations:
tuan thanh » thuan thanh, quan thanh, tran thanh
hieu sach » chieu sach, dien sach, hieu cac
hieu cach » hieu cac, chieu sach, hieu ca
hang cong » dang cong, hang nong, bang cong
cong tuan » cong tan, cong luan, cong thanh
thanh ban » thanh san, thanh van, thanh bac
trang va » hang va
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 (hieu cach)) - hanh ((trang va) or (tran van)) hang cong tuan thanh ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sach) OR (hieu cach)) - hanh ((trang va) OR (tran van)) hang cong tuan thanh ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sach) OR (hieu cach)) - hanh ((trang va) or (tran van)) hang cong tuan thanh ban".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sach) OR (hieu cach)) - hanh ((trang va) or (tran van)) hang cong tuan thanh ban*.