Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
co sach » cuon sach, hoc sach
tuc van » thuc van, truc van, tuc va
cac tuc » cac toc, cac tu, cac tac
hieu ve » hieu va, hieu van
bo sach » hoc sach
ly hang » ly quang
cuc tre » duc tre, cua tre, cuu tre
ve cac » va cac, vien cac
y hang » ty hang, yu hang, _ hang

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