Perhaps you should try some spelling variations:
vanh dai » van dai, vanh tai, van dao
te sach » toc sach
sach ty » sach y, sach tu, sach thu
cac dac » cac dan, cac dai, cac bac
cuu tre » cua tre, cau tren, cau treo
cac duc » cac du, cao duc, cac nuoc
hieu va » lieu va, hieu qua
ty nang » ky nang, ty xang, ty hang
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ty nang x hoi. hieu va ((cac duc) or (cac dac)) va ((vanh dai) OR (lanh dao)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang x hoi. hieu va ((cac duc) OR (cac dac)) va ((vanh dai) OR (lanh dao)) cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty nang x hoi. hieu va ((cac duc) or (cac dac)) va ((vanh dai) OR (lanh dao)) cuu tre*".