Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
danh di » danh du, xanh di, danh dien
banh di » xanh di, banh chi, vanh dai
duc ban » duc tan, duc van, dua ban
cuu tre » cua tre, cau tren, cau treo
xuc ban » cuc ban, quoc ban, xuat ban
hieu va » lieu va, hieu qua
va cam » va cham, va cac, va cao
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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 nang o hoi. hieu va cam ((xuc ban) OR (duc ban)) ((banh di) or (danh di)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang o hoi. hieu va cam ((xuc ban) OR (duc ban)) ((banh di) OR (danh di)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang o hoi. hieu va cam ((xuc ban) OR (duc ban)) ((banh di) or (danh di)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang o hoi. hieu va cam ((xuc ban) OR (duc ban)) ((banh di) or (danh di)) cuu tre*.