Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van ban
su sach » so sach, vu sach
van anh » van thanh, tuan anh, van minh
dau xac » dau xay, dan xac
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
va nang » van nang, da nang, cam nang
v nang » vu nang, van nang, voi nang
vi cua » vai cua, di cua
va dau » va dao

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

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