Perhaps you should try some spelling variations:
sach thue » sach thieu, sach tham, cach thuc
sach thu » sach thieu, sach tham, cach thuc
diem cau » dieu can
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
dam tu » nam tu, cam tu, tam tu
di cau » da cau
va dam » van dam, va dao, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach thu) OR (sach thue)) nang xa hoi. hieu va dam tu va hanh ((di cau) or (diem cau)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach thu) OR (sach thue)) nang xa hoi. hieu va dam tu va hanh ((di cau) OR (diem cau)) tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach thu) OR (sach thue)) nang xa hoi. hieu va dam tu va hanh ((di cau) or (diem cau)) tren".
• Adding a wildcard symbol may retrieve word variants: te ((sach thu) OR (sach thue)) nang xa hoi. hieu va dam tu va hanh ((di cau) or (diem cau)) tren*.