How does the feedly.com search work without using google´s custom search API? https://developers.google.com/custom-search/
That´s how they generate search requests:
function l(w, x, y) {
var v = "feed/http://news.google.com/news?q=" + encodeURIComponent(w) + "&ie=UTF-8&ned=us&nolr=1&output=atom";
(from https://s3.feedly.com/web/28.0.980/js/10101_web02.js)
...but e.g. if I enter http://news.google.com/news?q=stackoverflow&ie=UTF-8&ned=us&nolr=1&output=atom I just get a normal search response from google, but no atom feed output.