Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
cuu tre » cua tre, cau tren, cau treo
cac duc » cac du, cac dac, cac nuoc
tai cuu » tai cuc, tai buu, tai cua
nang ro » nang co, nang ho, nang ra
hieu ve » hieu va, hieu van
cao duc » dao duc, cao suc, giao duc
tu sac » tu sach, tu cac, tu bac
ro lai » o lai, ho lai, ru lai
tu san » thu san, tu ban, tu can

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sac) or (tu san)) ky nang ro lai. hieu ve ((cac duc) OR (cao duc)) van hanh tai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sac) OR (tu san)) ky nang ro lai. hieu ve ((cac duc) OR (cao duc)) van hanh tai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sac) or (tu san)) ky nang ro lai. hieu ve ((cac duc) OR (cao duc)) van hanh tai cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sac) or (tu san)) ky nang ro lai. hieu ve ((cac duc) OR (cao duc)) van hanh tai cuu tre*.