Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
lang mai » lang dai, lang hai, lang man
hanh vai » hanh vi, hanh va, hanh tai
sach ky » sac ky, sach y, sach ty
vai cuu » vai cua
tu sach » thu sach, su sach, te sach
hieu ve » hieu va
mai hoi » mai khoi, dai hoi, lai hoi
ky lang » ky nang, ky dang, ky tang
cuu tre » cua tre, cau tren, cau treo
xuc va » duc va, tuc va, xac va
luc va » duc va, tuc va, loc 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 ky lang mai hoi. ((hieu ve) or (hieu van)) cam ((xuc va) OR (luc va)) hanh vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang mai hoi. ((hieu ve) OR (hieu van)) cam ((xuc va) OR (luc va)) hanh vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang mai hoi. ((hieu ve) or (hieu van)) cam ((xuc va) OR (luc va)) hanh vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang mai hoi. ((hieu ve) or (hieu van)) cam ((xuc va) OR (luc va)) hanh vai cuu tre*.