Perhaps you should try some spelling variations:
sach bao » sach dao, sach bac, cach bao
dua tren » dung tren
sach bai » sach dao, cac bai, sach xa
nano cau » nang cau, bang cau, nano va
ban hanh » ban hang
hanh va » hang va, hanh vi
cuu tre » cua tre, cau tren, cau treo
xuc ban » duc ban, cuc ban, quoc ban
hieu va » lieu va, hieu qua
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu ((sach bao) OR (sach bai)) nano cau hoi. hieu va cam xuc ban hanh va ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu ((sach bao) OR (sach bai)) nano cau hoi. hieu va cam xuc ban hanh va ((dua tren) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu ((sach bao) OR (sach bai)) nano cau hoi. hieu va cam xuc ban hanh va ((dua tren) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: vu ((sach bao) OR (sach bai)) nano cau hoi. hieu va cam xuc ban hanh va ((dua tren) or (cuu tre))*.