Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
hanh ca » hanh cac, hanh cat, hanh cua
va hanh » van hanh, va thanh, va danh
cam luc » cam xuc, cau luc
hieu va » lieu va, hieu qua
sach ky » sach y, sach ty, sach kem
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
sac ky » cac ky, sai ky
luc va » duc va, tuc va, loc va
ca cua » co cua
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat ((sach ky) OR (sac ky)) nang o hoi. ((hieu van) or (hieu va)) cam luc va hanh ca cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat ((sach ky) OR (sac ky)) nang o hoi. ((hieu van) OR (hieu va)) cam luc va hanh ca cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat ((sach ky) OR (sac ky)) nang o hoi. ((hieu van) or (hieu va)) cam luc va hanh ca cua tre*".