Perhaps you should try some spelling variations:
tu trong » tu tuong, tu tieng
thanh va » thanh van, hanh va, thanh ha
thanh ve » hanh ve, thanh vien, thanh van
sach vu » sach va, sach tu, sach uu
vuc ban » vu ban, duc ban, cuc ban
su sach » so sach, vu sach
vu nang » vuc nang, va nang, vu dang
hieu va » lieu va, hieu qua
cao vuc » cao duc, cao suc, cao vu
va cao » va cac, va co, va dao
x hoi » o hoi, x ho, 5 hoi

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 vu nang ((x hoi) or (xa hoi)). hieu va cao vuc ban ((thanh ve) OR (thanh va)) tu trong~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach vu nang ((x hoi) OR (xa hoi)). hieu va cao vuc ban ((thanh ve) OR (thanh va)) tu trong.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach vu nang ((x hoi) or (xa hoi)). hieu va cao vuc ban ((thanh ve) OR (thanh va)) tu trong".
• Adding a wildcard symbol may retrieve word variants: su sach vu nang ((x hoi) or (xa hoi)). hieu va cao vuc ban ((thanh ve) OR (thanh va)) tu trong*.