array(3) {
  [0]=>
  int(15884)
  [1]=>
  string(195) "McMahan B., Moore E., Ramage D., Hampson S., Arcas B.A. Communication-Efficient Learning of Deep Networks from Decentralized Data // Artificial intelligence and statistics. 2017. pp. 1273–1282."
  [2]=>
  int(1)
}
<h1>DB Error 230: Duplicate entry '15884-1' for key 'citations.citations_submission_seq'</h1>