Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
toc sach » hoc sach, doc sach, thuoc sach
nang mai » nang ma, nang tai, lang mai
sach ky » sac ky, sach y, sach ty
vai cuu » vai cua
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
hieu ve » hieu van
mai hoi » mai khoi, dai hoi, lai hoi
xac va » tac va, ac va, bac 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: toc sach ky nang mai hoi. ((hieu ve) OR (hieu va)) cam ((xac va) or (luc va)) thanh vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang mai hoi. ((hieu ve) OR (hieu va)) cam ((xac va) OR (luc va)) thanh vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang mai hoi. ((hieu ve) OR (hieu va)) cam ((xac va) or (luc va)) thanh vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang mai hoi. ((hieu ve) OR (hieu va)) cam ((xac va) or (luc va)) thanh vai cuu tre*.