Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
thu sach » thuat sach, thuoc sach, thu hoach
tu sach » su sach, te sach, tu cach
dao tuc » dao duc
dao xuc » dao duc, dao xu, dao xuan
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
va nang » van nang, da nang, cam nang
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: ((tu sach) OR (thu sach)) va nang xa hoi. hieu va ((dao xuc) or (dao tuc)) van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) va nang xa hoi. hieu va ((dao xuc) OR (dao tuc)) van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) va nang xa hoi. hieu va ((dao xuc) or (dao tuc)) van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) va nang xa hoi. hieu va ((dao xuc) or (dao tuc)) van hanh vi cua tre*.