Perhaps you should try some spelling variations:
danh vinh » dang vinh, anh vinh, thanh vinh
danh dinh » dang dinh, anh dinh, dinh dinh
cau treo » cau theo, cau tren, cau triet
sach thu » sach thue, sach thieu, sach tham
thu nang » thi nang, thu hang, thu bang
hieu van » hieu va, thien van, lieu va
te sach » toc sach
van dau » van dao, phan dau
dau xac » dau xay, dan xac
xac va » tac va, ac va, bac va
o hoc » co hoc, mo hoc, so hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach thu nang ((o hoc) or (x ho)). hieu van dau xac va ((danh dinh) OR (danh vinh)) cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach thu nang ((o hoc) OR (x ho)). hieu van dau xac va ((danh dinh) OR (danh vinh)) cau treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach thu nang ((o hoc) or (x ho)). hieu van dau xac va ((danh dinh) OR (danh vinh)) cau treo".
• Adding a wildcard symbol may retrieve word variants: te sach thu nang ((o hoc) or (x ho)). hieu van dau xac va ((danh dinh) OR (danh vinh)) cau treo*.