Perhaps you should try some spelling variations:
thanh dam » thanh dat, thanh nam, thanh tam
nang dai » nang dau, nang tai, lang dai
hanh dao » lanh dao, thanh dat, doanh dao
so sach » so sanh, bo sach, co sach
cam tuc » cam xuc, cam tu, nam thuc
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
hieu ve » hieu van
dai hoa » dai khoa, dai hoc, dai hoi
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky nang dai hoa. ((hieu ve) or (hieu va)) cam tuc va ((hanh dao) OR (thanh dam)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang dai hoa. ((hieu ve) OR (hieu va)) cam tuc va ((hanh dao) OR (thanh dam)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky nang dai hoa. ((hieu ve) or (hieu va)) cam tuc va ((hanh dao) OR (thanh dam)) cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ky nang dai hoa. ((hieu ve) or (hieu va)) cam tuc va ((hanh dao) OR (thanh dam)) cua tre*.