Perhaps you should try some spelling variations:
thanh tai » thanh toan, doanh tai, thanh san
thanh hai » thanh phan, thanh hoa, thanh san
co sach » bo sach, cuon sach, hoc sach
cac toc » cac toi, cac nuoc, cac thoi
cuc tre » duc tre, cua tre, cuu tre
sach ly » sach y, sach lo, sach ty
cac tuc » cac tu, cac tac, cac nuoc
hieu ve » hieu va, hieu van
hang xa » hoang xa, hang va, hang ca
ly hang » ly quang

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

• Performing a fuzzy search may retrieve terms with similar spellings: co sach ly hang xa hoi. hieu ve ((cac tuc) OR (cac toc)) van ((thanh tai) or (thanh hai)) cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach ly hang xa hoi. hieu ve ((cac tuc) OR (cac toc)) van ((thanh tai) OR (thanh hai)) cuc tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach ly hang xa hoi. hieu ve ((cac tuc) OR (cac toc)) van ((thanh tai) or (thanh hai)) cuc tre".
• Adding a wildcard symbol may retrieve word variants: co sach ly hang xa hoi. hieu ve ((cac tuc) OR (cac toc)) van ((thanh tai) or (thanh hai)) cuc tre*.