Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
chat huu » pham huu
chat xuc » cam xuc, chao xu, chat cua
sach tu » sach thu, sach ty, sach uu
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
cach tu » cach thuc
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((sach tu) OR (cach tu)) nang xa hoi. hieu ve ((chat xuc) or (chat huu)) van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach tu) OR (cach tu)) nang xa hoi. hieu ve ((chat xuc) OR (chat huu)) van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach tu) OR (cach tu)) nang xa hoi. hieu ve ((chat xuc) or (chat huu)) van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: toc ((sach tu) OR (cach tu)) nang xa hoi. hieu ve ((chat xuc) or (chat huu)) van hanh vi cua tre*.