Perhaps you should try some spelling variations:
sach tao » sach dao, sach tai, sach tham
sach bao » sach dao, sach bai, sach bac
van hanh » van thanh, ban hanh, van anh
cua tre » cua te, cua triet, dua tren
hanh va » hang va, hanh vi
xuc van » duc van, luc van, vuc van
cuu tre » cau tren, cau treo
hieu va » lieu va, hieu qua
nano xa » nano va, nano bac, nano cau
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: co ((sach tao) OR (sach bao)) nano xa hoi. hieu va cam xuc van hanh va ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co ((sach tao) OR (sach bao)) nano xa hoi. hieu va cam xuc van hanh va ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "co ((sach tao) OR (sach bao)) nano xa hoi. hieu va cam xuc van hanh va ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: co ((sach tao) OR (sach bao)) nano xa hoi. hieu va cam xuc van hanh va ((cua tre) or (cuu tre))*.