Executing multiple HTTP requests sequentially using async.js

How can I execute multiple HTTP requests sequentially using async.js . I checked the async.js documentation but couldn't figure out, how to do that. I want to achieve the same thing as below code using async.js callback style.

var http = require('http');
var Q = require('q');
var URL="http://localhost:3000";

var getPromise=function(url) {  
  var deferred  = Q.defer();
  var req = http.get(url, function(response) {
    if(response.statusCode < 200 || response.statusCode > 299){
            deferred.reject(new Error('ErrorCode '+response.statusCode))
        }   
      var result="";
        response.on('data',function(chunk){result +=chunk;} )
        response.on('end',function(){deferred.resolve(result);} ) 
  });

  req.on('error',function(err){
      console.error('Error with the request:', err.message); 
      deferred.reject(err); 
  });

  req.end();  
  return deferred.promise;
} 


getPromise('http://localhost:3000/olympic/2016/ranking/4')
      .then(function(data){
         console.log("Response 1 "+data)
         return getPromise(URL+'/iso/country/'+JSON.parse(data).Country);
      })
      .then(function(data){
         console.log("Response 2 "+data)
         return getPromise(URL+'/olympic/2016/medal/'+JSON.parse(data).iso);
      })
      .then(function(data){
        console.log("Response 3 "+data)
      })
      .catch(function(err){
         console.log(err)
      });

via Mahtab Alam