Perhaps you should try some spelling variations:
dan thanh » dang thanh, danh thanh, van thanh
ban thanh » ban hanh, ban hang
sach thi » sach thu, sach tai, sach thieu
thi hang » thi hanh, thi nang, thi hong
hieu ve » hieu va, hieu van
hang xa » hoang xa, hang va, hang ca
su sach » so sach, vu sach
dam su » dan su, dat su, dam tu
ve am » va am
da su » dan su, dat su, va su

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach thi hang xa hoi. hieu ve am thuc ((dan thanh) OR (ban thanh)) ((dam su) or (da su)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thi hang xa hoi. hieu ve am thuc ((dan thanh) OR (ban thanh)) ((dam su) OR (da su)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thi hang xa hoi. hieu ve am thuc ((dan thanh) OR (ban thanh)) ((dam su) or (da su)) triet".
• Adding a wildcard symbol may retrieve word variants: su sach thi hang xa hoi. hieu ve am thuc ((dan thanh) OR (ban thanh)) ((dam su) or (da su)) triet*.