Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
cau theo » cau thi, cau tao
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, ban thanh, va tinh
cua tre » cua te, cuu tre, cua triet
cac tac » cac toc, cac bac, cac dac
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va
ty nang » ky nang, ty xang, ty hang
tac va » tac da, tac xa, tuc va
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: tu sach ty nang x hoi. ((hieu ve) OR (hieu van)) cac tac va thanh hai ((cua tre) or (cau theo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang x hoi. ((hieu ve) OR (hieu van)) cac tac va thanh hai ((cua tre) OR (cau theo)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang x hoi. ((hieu ve) OR (hieu van)) cac tac va thanh hai ((cua tre) or (cau theo))".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang x hoi. ((hieu ve) OR (hieu van)) cac tac va thanh hai ((cua tre) or (cau theo))*.