Perhaps you should try some spelling variations:
hanh tri » thanh tri, hanh tai, hanh trinh
ban hanh » ban hang
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
pho hai » pho ha
sac ky » cac ky, sai ky
ho hai » hoc hai, cho hai, ho hap
tu sac » tu sach, tu cac, tu san

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 ky nang ((ho hai) OR (pho hai)). hieu ve ((cac nuoc) or (cam xuc)) ban hanh tri cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang ((ho hai) OR (pho hai)). hieu ve ((cac nuoc) OR (cam xuc)) ban hanh tri cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang ((ho hai) OR (pho hai)). hieu ve ((cac nuoc) or (cam xuc)) ban hanh tri cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang ((ho hai) OR (pho hai)). hieu ve ((cac nuoc) or (cam xuc)) ban hanh tri cua tre*.