Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh vai » thanh hai, thanh van, thanh tai
dua tren » dung tren
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cua triet, cua thep
tu sach » thu sach, su sach, te sach
ky dang » ky nang, ky danh
dang ma » dang mau, dang mam, dang mat
cuu tre » cau tren, cau treo
da ban » dia ban, dua ban, day ban
van ca » van cau, van cua, dan ca
ca da » ca dao, ca dan, ca dam

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 dang ma hoa. hieu van ca da ban thanh vai ((((cua tre) OR (dua tren))) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky dang ma hoa. hieu van ca da ban thanh vai ((((cua tre) OR (dua tren))) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky dang ma hoa. hieu van ca da ban thanh vai ((((cua tre) OR (dua tren))) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky dang ma hoa. hieu van ca da ban thanh vai ((((cua tre) OR (dua tren))) or (cuu tre))*.