Perhaps you should try some spelling variations:
cuon sach » duong sach, cuoc cach, co sach
hanh tai » thanh tai, hang tai, han tai
le quang » vu quang
hieu ve » hieu va, hieu van
ly hang » ly quang
cuc tre » duc tre, cua tre, cuu tre
ve cac » va cac, vien cac
tuc va » thuc va, truc va, duc va

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

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