Perhaps you should try some spelling variations:
sach bao » sach dao, sach bai, sach bac
dua tren » dung tren
ban hanh » ban hang
nano cau » nang cau, bang cau, nano va
hanh va » hang va, hanh vi
cuc ban » cua ban, cac ban, cuu ban
cam cuc » cam xuc, cham cuu, pham cuc
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
sach xa » sach dao, sach nha, sach bai
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 xa)) nano cau hoi. hieu va cam cuc 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 xa)) nano cau hoi. hieu va cam cuc ban hanh va ((dua tren) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: vu ((sach bao) or (sach xa)) nano cau hoi. hieu va cam cuc ban hanh va ((dua tren) or (cuu tre))*.