Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thai cua » than cua, tai cuc, tri cua
dan thai » dang thai, dan thi, dan than
te sach » toc sach
cac tac » cac toc, cac bac, cac dac
sach ty » sach y, sach tu, sach thu
cac tuc » cac toc, cac tu, cac nuoc
ty nang » ky nang, ty xang, ty hang
cua tre » cua te, cuu tre, cua triet
va dan » ca dan, va dao, va dau
x hoi » xa hoi, o hoi, 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: te sach ty nang ((x hoi) OR (x ho)). hieu van ((cac tuc) or (cac tac)) va dan thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang ((x hoi) OR (x ho)). hieu van ((cac tuc) OR (cac tac)) va dan thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty nang ((x hoi) OR (x ho)). hieu van ((cac tuc) or (cac tac)) va dan thai cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty nang ((x hoi) OR (x ho)). hieu van ((cac tuc) or (cac tac)) va dan thai cua tre*.