Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty sang » ty xang, ty hang, duy sang
hieu ve » hieu va, hieu van
cuc tre » duc tre, cua tre, cuu tre
ma hoi » mai hoi, ma hoa, me hoi
ve cac » va cac, vien cac
xuc va » tuc va, luc va, xac va

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

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