Perhaps you should try some spelling variations:
ban nhanh » ban thanh, ban nhan, nhan nhanh
ban hanh » ban hang
cau tren » cu tren, dau tren, ca tren
bo sach » co sach, hoc sach
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
cao duc » dao duc, cao suc, giao duc
ve cao » va cao, ve bao, ve cac
li cau » loi cau, li ca, le cau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((bo sach) or (su sach)) ky nang x ho. hieu ve cao duc ((ban nhanh) or (ban hanh)) li cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((bo sach) OR (su sach)) ky nang x ho. hieu ve cao duc ((ban nhanh) OR (ban hanh)) li cau tren.
• Adding a wildcard symbol may retrieve word variants: ((bo sach) or (su sach)) ky nang x ho. hieu ve cao duc ((ban nhanh) or (ban hanh)) li cau tren*.