Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cau treo » cau theo, cau tren, cau triet
coc thuc » doc thuc, co thuc, cong thuc
hoc thuc » hoc huu
thanh ve » hanh ve, thanh va, thanh vien
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
v nang » va nang, vu nang, van nang
sach v » sach va, sach y, sach 2
x hoi » xa hoi, o hoi, x ho

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 v nang x hoi. hieu ve ((coc thuc) OR (hoc thuc)) ban thanh ve ((cau treo) or (cau thi))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach v nang x hoi. hieu ve ((coc thuc) OR (hoc thuc)) ban thanh ve ((cau treo) OR (cau thi)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach v nang x hoi. hieu ve ((coc thuc) OR (hoc thuc)) ban thanh ve ((cau treo) or (cau thi))".
• Adding a wildcard symbol may retrieve word variants: tu sach v nang x hoi. hieu ve ((coc thuc) OR (hoc thuc)) ban thanh ve ((cau treo) or (cau thi))*.