Perhaps you should try some spelling variations:
nhanh thai » nhanh thi, nhanh thanh, nhanh thang
van nhanh » van thanh, van hanh, van khanh
thai cua » than cua, tai cuc, tri cua
cao tang » cao dang
cua tre » cua te, cuu tre, cua triet
cam duc » cam xuc, cao duc, pham duc
hieu ve » hieu van
hieu va » lieu va, hieu qua
duc van » duc va, duc tan, duc manh
su sai » su tai, su hai, su dai

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sai ((kho tang) or (cao tang)) xa hoi. ((hieu ve) OR (hieu va)) cam duc van nhanh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sai ((kho tang) OR (cao tang)) xa hoi. ((hieu ve) OR (hieu va)) cam duc van nhanh thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sai ((kho tang) or (cao tang)) xa hoi. ((hieu ve) OR (hieu va)) cam duc van nhanh thai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sai ((kho tang) or (cao tang)) xa hoi. ((hieu ve) OR (hieu va)) cam duc van nhanh thai cua tre*.