Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, ban thanh, va tinh
xa thanh » ha thanh, ta thanh, gia thanh
su sach » so sach, vu sach
ban tum » ban tu
nang xa » nang x, lang xa, nang ma
vu nang » vuc nang, va nang, vu dang
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: ((su sach) or (do sanh)) vu nang xa hoi. hieu van ban tum ((xa thanh) OR (va thanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (do sanh)) vu nang xa hoi. hieu van ban tum ((xa thanh) OR (va thanh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (do sanh)) vu nang xa hoi. hieu van ban tum ((xa thanh) OR (va thanh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (do sanh)) vu nang xa hoi. hieu van ban tum ((xa thanh) OR (va thanh)) vi cua tre*.