Perhaps you should try some spelling variations:
tan nhanh » tai nhanh, tan nhan, tan thanh
sach dai » sach dao, sach bai, sach dau
sach dat » sach dao, sach danh, sach bai
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
hai cua » thai cua, dai cua, lai cua
hoi cua » hoi chuc

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 dai) OR (sach dat)) nang xa hoi. hieu va cac duc tan nhanh ((hai cua) or (hoi cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach dai) OR (sach dat)) nang xa hoi. hieu va cac duc tan nhanh ((hai cua) OR (hoi cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach dai) OR (sach dat)) nang xa hoi. hieu va cac duc tan nhanh ((hai cua) or (hoi cua)) tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach dai) OR (sach dat)) nang xa hoi. hieu va cac duc tan nhanh ((hai cua) or (hoi cua)) tre*.