#20 Notice: Only variable references should be returned by refer

[Cipher Chien]

an error message occur when some class get api like this:
return $this->_request->getApi();

it will show the error message Notice: Only variable references should be returned by reference in C:\Web\.....\Phlickr\PhotoList.php on line 117
My solution is:
public function &getApi() {
$api = $this->_request->getApi();
return $api;
}

[Anonymous]

I'm also seeing this type of error:

PHP Notice: Only variable references should be returned by reference in /Users/mcarter/Sites/Gallery2Flickr/Phlickr/Framework/ListBase.php on line 100

This occurred whilst using the sample code to upload a batch of images and create a set for them,..