Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
nang xay » dang xay, nganh xay, nang xuan
cau treo » cau theo, cau tren, cau triet
hoc sach » hoc sinh, hoc cac, hoc anh
xay hoi » xa hoi, tay hoi, cay phoi
hieu ca » hieu cac, hieu cua, hieu va
dan vat » dang vat, van vat, dan va
cuu tre » cua tre, cau tren
thu ca » thu cua, thu ha, thu ba
ca dan » cac dan, ca dao
ca nam » cua nam, cai nam, ha nam

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) OR (hoc sach)) ky nang xay hoi. hieu ca nam thu ca dan vat ((cuu tre) or (cau treo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) ky nang xay hoi. hieu ca nam thu ca dan vat ((cuu tre) OR (cau treo)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (hoc sach)) ky nang xay hoi. hieu ca nam thu ca dan vat ((cuu tre) or (cau treo))".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (hoc sach)) ky nang xay hoi. hieu ca nam thu ca dan vat ((cuu tre) or (cau treo))*.