Perhaps you should try some spelling variations:
thanh hoi » thanh hoai, thanh hoa, thanh hai
ban thanh » ban hanh, ban hang
cham cua » chat cua, cham cuu, pham cua
tu sach » thu sach, su sach, te sach
hoi cuu » hoi chu, hoi cua, ho cuu
ham cua » pham cua, hai cua, nam cua
hieu ve » hieu va, hieu van
dai moi » doi moi, dai hoi
mai hoi » mai khoi, dai hoi, lai hoi
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang

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 y nang ((mai hoi) or (dai moi)). hieu ve ((cham cua) OR (ham cua)) ban thanh hoi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((mai hoi) OR (dai moi)). hieu ve ((cham cua) OR (ham cua)) ban thanh hoi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ((mai hoi) or (dai moi)). hieu ve ((cham cua) OR (ham cua)) ban thanh hoi cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((mai hoi) or (dai moi)). hieu ve ((cham cua) OR (ham cua)) ban thanh hoi cuu tre*.