Perhaps you should try some spelling variations:
van nang » van quang, van ban, van dong
voi nang » voi hang, hoi nang, voi rang
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
va lang » va nang, hoa lang
lang vi » hang vi, lang va, sang vi
cua tre » cua te, cuu tre, cua triet
v nang » va nang, vu nang, vuc 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: su sach ((((v nang) OR (voi nang))) or (van nang)) xa hoi. hieu va cac nuoc va lang vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((((v nang) OR (voi nang))) OR (van nang)) xa hoi. hieu va cac nuoc va lang vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((((v nang) OR (voi nang))) or (van nang)) xa hoi. hieu va cac nuoc va lang vi cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((((v nang) OR (voi nang))) or (van nang)) xa hoi. hieu va cac nuoc va lang vi cua tre*.